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 ARAOHNIDA

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genital somite, would then have to be supposed to have occuired also. Sub - order a. Uropygi. — Prosoma longer than wide, its sternal area very narrow, furnished with a large prosternal and metasternal plate, and often with a small mesosternal-sclente. Appendages of 2nd pair with their basal segments united in the middle line and incapable of lateral movement; appendages of 3rd pair with only the apical segment many-jointed. Opisthosoma without trace of appendages ; its posterior somites narrowed to form ■9

Family —Hubbardiidae {Schizomus, Huhlardia) (Figs. 57-59). Sub-order h. Amblypygi.—Prosoma wider than long, covered above by a single shield bearing median and lateral eyes, which have diplostichous ommatea. Sternal area broad, with prosternal, two mesosternal, and metasternal plates, the prosternum projecting forwards beneath the coxse of the 2nd pair of appendages. Appendages of 2nd pair folding in a horizontal plane ; their basal segments freely movable ; claw free or fused ; basal segments of 4th and 5th pairs widely separated by the sternal area ; appendages of 3rd pair with all the segments except the proximal three, forming a manyII lit IV V VI 5 11 pa

opistho 1 opistho 2

m Fig. 56.—Thelyphonus assamensis S- Ventral surface of the anterior region of the opisthosoma, the first somite being pushed upwards and forwards so as to expose the subjacent structures, opistho 1, First somite of the opisthosoma ; opistho 2, second do.; g, genital aperture; l, edges of the lamell® of the lung-books ; to, stigmata of tergo-sternal muscles. (Original drawing by Mr. Pocock.) a movable tail for the support of the post-anal sclerite, which has no poison glands. Tribe 1. Urotricha.—Dorsal area of prosoma covered with a single shield (? two in Geralinura), bearing median and lateral eyes. Post-anal sclerite modified as a long, many-jointed feeler. Appendages of 2nd pair folding in a horizontal plane, completely chelate, the claw immovably united to the sixth segment. Respiratory organs present in the form of pulmonary sacs. Family—Thelyphonidee {Thelyphonus (Fig. 54), Hypoctonus, Tribe 2. Tartarides.—Small degenerate, forms with the dorsal area of the prosoma furnished with two shields, a larger in front
 * Geralinura).

Fig. 57. —- Schizomus crassicaudatus, one of the Tartarid Pedipalpi. Ventral view of a female with the appendages cut short near the base, a, Prosternum of prosoma; b, metasternum of prosoma; prce-gen, the prse-genital somite; 1 opisth, first somite of the opisthosoma ; 11 opisth, eleventh somite of the opisthosoma ; pa, post-anal lobe of the female (compare the jointed filament in Thelyphonus, Fig. 54). (Original drawing by Mr. Pickard-Cambridge, directed by Mr. Pocock.)

Fig. 58.—Schizomus crassicaudatus, a Tartarid Pedipalp. Dorsal view of a male with the appendages cut short. I to VI, the prosomatic appendages; a, anterior plate, and 6, posterior plate of the prosomatic carapace; prce-gen, tergum of the prse-genital somite; 11, the eleventh somite of the opisthosoma; pa, post-anal lobe of the male—a conical body with narrow basal stalk. (Original as above.)

covering the anterior four somites, and a smaller behind covering the 5th and 6th somites; the latter generally subdivided into a right and left portion ; rarely there is a pair of narrow sclerites interposed between the anterior and posterior shields. Eyes evanescent or absent. Appendages of 2nd pair folding in a vertical plane, not chelate, the claw long and movable. Post-anal sclerite short and undivided. No distinct respiratory stigmata behind the sterna of the 1st and 2nd somites of the opisthosoma.

Fig. 59.—Schizomus crassicaudatus, one of the Pedipalpi. Lateral view of a male. II to VI, the prosomatic appendages, the first being concealed (see Fig. 58) ; 5, the fifth, and 11, the eleventh tergites of the opisthosoma ; pa, the conical post-anal lobe. (Original as above.) jointed flagellum. Opisthosoma without post-anal sclerite and posterior caudal elongation : with frequently a pair of small lobate appendages on the sternum of the 3rd somite. Respiratory organs, as in Urotricha. Family—Phrynichidae {Phrynichus, Damon). ,, Admetidae {Admetus, Heterophrynus). ,, Charontidae {Charon, Sarax). (Family ?)—*Geraphrynus. Remarks.—The Pedipalpi are confined to the tropics and warmer temperate regions of both hemispheres. Fossil forms occur in the Carboniferous. The small forms known as Schizomus and Hubbardia are of special interest from a morphological point of view. The Pedipalpi have no poison glands. (Reference to literature (29).) Order 3. Araneae (Figs. 60 to 64). — Prosoma covered with a single'shield and typically furnished with median and lateral eyes of diplostichous structure, as in the Amblypygi. Its sternal ' surface wide, continuously chitinized, but with prosternal and

and behind the prosomatic carapace is seen the tergite of the small praegenital somite. (Original by Pickard-Cambridge and Pocock.) metasternal elements generally distinguishable at the anterior and posterior ends respectively of the large mesosternum. Prosternum underlying the proboscis. Appendages of 1st pair have two segments, as in Pedipalpi, but are furnished with poison gland, and are retroverts. Appendages of 2nd pair not underlying the mouth, but freely movable and, except in primitive forms, furnished with a maxillary lobe ; the rest of the limb like the legs, tipped with a single claw and quite unmodified (except in d ).