Page:Encyclopædia Britannica, Ninth Edition, v. 12.djvu/707

689 CLASSIFICATION.] ICHTHYOLOGY 689 pterodon, Pachymetopon, Dipterodon, Gymnocrotaphus, Girclla, Tephroeops, Doydixodon, Haplodactylus, Sargiis (Sheep s Head), Lethrinus, Sphcerodon, Pag r us, Pagellus, Chrysophrys, and Pimc- lepterus. The extinct forms found hitherto are rather numerous : the oldest come from the Cretaceous formation of Mount Lebanon ; some belong to living genera, as Sarqus, Pagellus ; of others from Eocene and Miocene formations no living representative is known Sparn- odus, Sargodon, Capitodus, Soricidens, Asima. The Hoplognathidce are a very small family distinguished by confluent teeth, and allied to the sea-breams. Family 5. Cirrkitidas. BoAy oblong, compressed, covered with cycloid scales ; lateral line continuous. Mouth in front of the snout, with lateral cleft. Cheeks without a bony stay for the prajoper- culum. Dentition more or less complete, composed of small pointed teeth, sometimes with the addition of canines. One dorsal iin formed by a spinous and soft portion, of nearly equal development. Anal with three spines, generally less developed than the soft dorsal. The lower rays of the pectoral fins simple and generally enlarged ; ventrals thoracic, but remote from the root of the pectorals, with one spine and five rays. Genera : Cirrhitcs, Chironemus, C hilodactylus, Mendosoma, Ncma- dactylus, and Latris. Family 6. Scorpcenidce. Body oblong, more or less compressed, covered with ordinary scales or naked. Cleft of the mouth lateral or subvertical. Dentition feeble, consisting of villiform teeth, and generally without canines. Some bones of the head armed, especially the angle of the prseoperculum, its armature receiving additional support by a bony stay, connecting it with the infraorbital ring. The spinous portion of the dorsal fin equally or more de veloped than the soft and the anal. Ventrals thoracic, generally with one spine and five soft rays, sometimes rudimentary. Genera : Scbastes, Scorpccnn, Glyptauchen, Lioscorpius, Sctarches, Ptcrois, Apistus, Agriopus, Synanceia, Micropus, Chorismodaclylus, Tcenianotus, C entropogon, Pentaroge, Tctraroge, Prosopodasys, Aplo- actis, Trichopleura, Hemitriptcrus, Minous, and Pelor. Family 7. Nnndidr.e. Body oblong, compressed, covered with scales. Lateral line interrupted. Dorsal fin formed by a spinous and soft portion, the number of spines and rays being nearly equal ; anal fin with three spines, and with the soft portion similar to the soft dorsal. Ventral fins thoracic, with one spine, and five or four rays. Dentition more or less complete, but feeble. Genera : Plcsiops, Tmchinops, Badis, Nandus, and Catopra. Family 8. Polycentridce. Body compressed, deep, scaly. La teral line none. Dorsal and anal fins long, both with numerous spines, the spinous portion being the more developed. Ventrals thoracic, with one spine and five soft rays. Teeth feeble. Pseudo- branchiae hidden. Genera : Polyccntrus and Monocirrhus. Family 9. Teuthididcc. Rody oblong, strongly compressed, covered with very small scales. Lateral line continuous. A single series of cutting incisors in each jaw ; palate toothless. One dorsal fin, the spinous portion being the more developed ; anal with seven spines. Ventral fins thoracic, with an outer and an inner spine, and with three soft rays between. Genus : Teuthis. DIVISION II. Aeanthoptcrygil Bcryciformcs. Body compressed, oblong, or elevated ; head with large muciferous cavities, which are covered with a thin skin. Ventral fins thoracic, with one spine and more than five soft rays (in Monoccntris with two only). The family of Bcrycidce has a very remarkable geographical dis tribution, which has been noticed at pp. 679, 681. Members of this family belong to the oldest Teleosteous fishes, the majority of the Acanthopterygians found in the Chalk being Berycoids. Beryx, Iloloccntrum, and Afyripristis have been found in several species, with other genera nowextinot: Pscudoberyx, Bcrycopsis, Homonotus, Stcnostoma, Sphcnoccphalus, Acanus, Hoploptcryx, Platycornus, Podocys, Acrogastcr, Macrolcpis, and lihacolcpis. Living genera : Monoccntris, Hoplostethus, Trachichthys, Anoplo- gastcr, Beryx, Melamphacs, Polymixia, Myripristis, andlfoloccntrum. DIVISION III. Acanthopterygii Kurtiformes. One dorsal fin only, much shorter than the anal, which is long and many-rayed. No superbranchial organ. One family, Kurtidcc. Genera : Pcmphcris and Kurtus. DIVISION IV. Acanthopterygii Polyncmiformcs. Two rather short dorsal fins, somewhat remote from each other ; free filaments at the humeral arch, below the pectoral fins ; muciferous canals of the head well developed. Family. Polynemidcc. Body oblong, rather compressed, covered with smooth or very feebly ciliated scales. Lateral line continuous. Snout projecting beyond the mouth, which is inferior, with lateral cleft. Eye lateral, largo. Villiform teeth in the jaws and on the palate. Ventrals thoracic, with one spine and five rays. Genera : Polyncmns, Pcntancmus, and Galcoidcs, DIVISION V. Acanthopterygii Scicuniformcs The soft dorsal is more, generally much more, developed than the spinous and the anal. No pectoral filaments ; head with the muciferous canals well developed. Family. Sciccnidce. Body rather elongate, compressed, covered with ctenoid scales. Lateral line continuous, and frequently extending over the caudal tin. Month in front of the snout. Eye lateral, of moderate size. Teeth in villiform bands, some times with the addition of canines ; no molars or incisor-like teeth in the jaws ; palate toothless. Praoperculum unarmed, and without bony stay. Ventrals thoracic, with one spine and five soft rays. Bones of the head with wide mnciferous channels. Air- bladder frequently with numerous appendages. Genera : Larimus, Pogonias (Dmm), Micropogon, Umlrina, Equcs, Nebris, LoncJiurns, Scicena (Meagre), Pachyurus, Otolithus, Ancylodon, and Collichthys. DIVISION VI. Acanthopterygii Xiphiiformcs. - The upper jaw is produced into a cuneiform weapon. One family, Xiphiidce (Sword-Fishes), with the genera Xiphias and Histiophorus. DIVISION VII. AcanthoptcrygiiTrichiuriformes. Body elongate, compressed or band-like ; cleft of the mouth wide, with several strong teeth in the jaws or on the palate. The spinous and soft portions of the dorsal fin and the anal are of nearly equal extent, long, many-rayed, sometimes terminating in finlets ; caudal fin forked, if present. The family of Trichiuridcc is composed of the following living genera: Nedlotus, Ncsiarchus, Aplmnopus Euoxymctopon, Lepidopus (Scabbard-Fish), Trlchiurvs (Hair-Tail), Epinnula, Thyrsites, and Gcmpylus. It was well represented in the Chalk and later forma tions by Enchodus, Anenchclum, Nemopteryx, Xiphoptcrus, Heini- thyrsites, and Trichiuriclitlujs. Two other genera, Palceorhynchus and Hemirhynchus, belong to a distinct though allied family. DIVISION VIII. Acanthojitcrygii Cotto-scombriformes.^&amp;gt;f c^ developed in one of the fins at least. Dorsal fins either continuous or close together ; the spinous dorsal, if present, always short ; sometimes modified into tentacles, orinto a suctorial disk ; soft dorsal always long, if the spinous is absent ; anal similarly developed as the soft dorsal, and both generally much longer than the spinous, sometimes terminating in finlets. Ventrals, thoracic or jugular, if present, never modified into an adhesive apparatus. No prominent anal papilla. Family 1. Acronuridcc. Body compressed, oblong or elevated, covered with minute scales. Tail generally armed with one or more bony plates or spines, which are developed with age, but absent in very young individuals. Eye lateral, of moderate size. Mouth small ; a single scries of more or less compressed, sometimes denticulated, sometimes pointed incisors in each jaw ; palate tooth less. One dorsal fin, the spinous portion being less developed than the soft ; anal with two or three spines ; ventral fins thoracic. Nine abdominal and thirteen caudal vertebra?. Genera : Acanthurus (Surgeon), Nascus, and Prionurus. Extinct species of Acanthurus and A ascus have been discovered in the Monte Bolca formation. Family 2. Carangidcc. Body more or less compressed, oblong or elevated, covered with small scales or naked ; eye lateral. Teeth, if present&amp;gt; conical. No bony stay for the prseoperculum. The spiuous dorsal is less developed than the soft or the anal, either continuous with, or separated from, the soft portion ; some times rudimentary. Ventrals thoracic, sometimes rudimentary or entirely absent. No prominent papilla near the vent. Gill- opening wide. Ten abdominal and fourteen caudal vertebra;. Genera : Caranx (Horse-Mackerel), Argyriosus, Micropteryx, Seriola, Seriolella, Seriolichthys (Yellow-Tails), Naucrates (Pilot- Fish), Chorinemus, Lichia, Temnodon (Blue-Fish), Ladarius, Paro2&amp;gt;sis, Trachynotus, Pammclas, Pscttus, Platax, Zanchts, Anomalops, Capros (Boar-Fish), Antigonia, Diretmus, Equula, and Gazza. Members of this family appear first in Cretaceous formations, where they are represented by Platax and some caranx- likc genera ( Corner and Aipichthys). They are more numerous in Tertiary formations, especially in the strata of Monte Bolca, where some still existing genera occur, as Zanclus, Platax, Caranx (Carangopsis], Argyriosus (Vomer), Lichia, Trachynotus. Of extinct genera the following belong to this family : Psciidovomcr (Licata), Amphistium, Archocus, Ductor, Plionemus (1), and Scmio- phorus. Family 3. Cyttidcc. Body elevated, compressed, covered with small scales, or with bucklers, or naked ; eye lateral. Teeth conical, small. No bony stay for the prreoperculum. Dorsal fin compoecd of two distinct portions. Ventrals thoracic. No prominent papilla near the vent. Gill-opening wide. More than ten abdominal and more than fourteen caudal vertebra?. Genera : Zeus (John Dory) and C&amp;gt;//lus. Family 4. Stromnteidcc. Bod} more or less oblong and com* pressed, covered with very small scales ; eye lateral. Dentition very feeble ; oesophagus armed with numerous horny, barbed pro cesses. No bony stay for the prseopereulum. Dorsal fin single, long, without distinct spinous division. More than ten abdominal and more than fourteen caudal vertebrae. XTI. 87