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 MARINE ZOOLOGY 3. Tubularia larynx y Ellis & Sol. My specimens have usually been obtained from the bottom of my yacht, and dead ones are so often seen in such situations that the species must be common all along the coast. Small groups are also occasionally dredged off Mersea. It is interesting to note that the original description of this species (1755) was probably based on Essex specimens, since Ellis refers to the abundance of the ' windpipe coralline ' ' near the mouth of the Thames, adhering to other marine bodies, and often to the bottoms of ships.' 4. Tubularia indivisa. Mr. Unthank gives this as found off Brightlingsea. Unfortunately in 1901 I was unable to obtain any specimens in order to be sure that I had found this species as well as T. larynx. 5. Eudendrium ramosum. Off Brightlingsea (H. W. Unthank). 6. Okelia gelatinosa (Pallas). Several fine specimens in my collection from the Orwell, and there can be little doubt as to its occurrence in Essex waters. 7. Clytia jahnstoni (Alder). Off Brightlingsea (H. W. Unthank). 8. Haledum halednum, Linn. The specimens collected were probably dredged off Mersea. 9. Sertularella po/yzoniai (Linn.). Found by Mr. Hope near Harwich. O. Sertularia putni/a, Linn. Found by Mr. Hope near Harwich at all seasons. The specimens show considerable variation in the thickness of the stems and attenuation of the internodes, some having all the characters of HassaU's species gracilis, which Mr. Hope thinks should probably be regarded as a variety of pumila. 1 1. Sertularia operculata, Linn. Found by Mr. Hope near Harwich. 12. Sertularia abietina, Linn. Found by Mr. Hope near Harwich. 13. Sertularia argentea, Ellis & Sol. Near Harwich (S. P. Hope). 14. Hytlrallmania falcata (Linn.). Near Harwich (S. P. Hope), and often dredged off Mersea and in other localities of Essex. 15. Antennularia antennina (Linn.). Near Harwich (S. P. Hope), and dredged in various other localities. 1 6. Plumularia setacea (Ellis). Specimens bearing gonophores from the Orwell, and probably occurs also in the neighbouring estuaries of Essex. 17. Plumularia echinulata, Lamarck. This appears to be a common species in Essex waters. Specimens taken near Harwich by Mr. Hope in June and October bear gonophores, and are attached to pieces of filamentous weeds and Zostera. 2. MEDUSJE The smaller medusae (Hydromedusar) are produced by lateral budding from various Hydroid stocks, e.g. Syncoryne, Obelia. The larger medusae (Discomedusae) do not always exhibit a similar alternation of stages in their life history, but Aurella and Chrysaora are known to be produced by a remarkable process of successive fission from minute Hydra-like polyps which form extensive colonies on old oyster shells and similar objects. A. Hydromeduste 1. Phia/idium, sp. var. Caught in a tow-net in the Wallet, but not well preserved. Probably many other species could be obtained if carefully looked for. B. Discomeduste 2. Chrysaora isosceles (Linn.). I have collected this in the Crouch at Burnham and in the Stour at Mistley, but more off Harwich than elsewhere, though I have never seen many. The colour seems to vary a good deal in different years, the upper surface being sometimes beautifully striped with brown, and sometimes scarcely marked at all. In 1899 I saw off Felixstowe one estimated to have a disk a foot in diameter and the appendages five or six feet long, but such are extremely rare. 3. Cyanea capillata (Linn.). This species occurs in nearly all localities, but is seldom or never very abundant. It grows to be more than a foot in diameter, and the tentacles are some few yards in length when fully extended. The usual colour is a creamy white, varying to a sort of orange colour. In 1901 I caught a specimen which seemed to differ from the above in having much shorter tentacles, but it was accidently destroyed before having been 77