On the ' Challenger ' Cejfhalopoda. 181 



on the chitinous coat and the surface of the other free at the 

 circumference ; cemented together and held in position by the 

 microcell-structure or " float," which, projecting above the 

 level of the outer heads of the birotules, gives rise to the 

 roughened state of the surface of the statoblast. Chitinous 

 coat and germinal contents the same as in the Spongillge 

 generally. Size of specimen sent to me about ^ x^ inch 

 horizontally. 



Hab. Fresh water. 



Log. " Ice-Factory Lakes, De Land, Florida, near the St. 

 John's River." 



Obs. The extremely delicate character of the spiculation 

 generally, the microspined skeletal spicules, the great length 

 of the birotules, and the radiating portions of the head being 

 horizontal and not recurved at their extremities, allies this 

 species more to Meyenia Jluviatilis than to the Heteromeyenice 

 (e. gr., Spongilla Baileyiy Bk., Proc. Zool. Soc. 1863, pi. 

 xxxviii. fig. 6) of Mr. Potts. Hence the name. 



XX. — Diagnoses of new Species of Cephalopoda collected during 

 the Cruise of H.M. 8. ' Challenger.'— Fsivt II. The Decapoda. 

 By William E. Hoyle, M.A. (Oxon), M.R.C.S., 

 F.R. S.E.J Naturalist to the ' Challenger ' Commission. 



[Published by permission of the Lords Commissioners of H.M. 

 Treasury, and extracted from a paper read before the Eoyal Society of 

 Edinburgh, July 6, 1885.] 



MyopsidaB. 

 Promachoteuthis, Hoyle. 



Promachoteuihis, Hoyle, 1885, Narr. Chall. Exp. vol. i. p. 273, fig. 109, 



The Body is short, rounded, with large broad fins, situated 

 posteriorly. The mantle is free behind, as in Rossia. The 

 siphon is short and slender and with everted margin ; valve ? 



The Head is small and narrow ; eyes not prominent. 



The Arms are long and conical, with two series of pedun- 

 culate spherical suckers. The tentacles exactly resemble the 

 arms at their origin ; the club is absent. 



The Gladius has not been removed from the single example. 



