244 PROCEEDINGS OF SOCIETIES. 



of North America, while the Mediterranean seas have yielded valuable 

 results to more than one able observer. To the researches of Leuckhart 

 and Gegenbaur we are particularly indebted. The former, in his 

 " Notes on the Medusae of the Seas of Nice" ("Wiegmann's "Archiv," 

 1856), describes ten new naked- eyed species, six of which belong to 

 established genera, and are named as follows : — Thaumantias corollata, 

 Oceania coccinea, JEuphysa globator, Steenstrupia lineata, Cunina moneta, 

 and Cunina costata. The four remaining species are made into as many 

 new genera : namely, Phialidium viridicans (which bears some resem- 

 blance to Thaumantias), Calyptra umbilicata, Pyxidium truncatum, and 

 Paryphasma planiusculum ; all four presenting novel and remarkable va- 

 rieties of structure. Gegenbaur' s paper (" Zeitschrift filer Wissenschaft- 

 liche Zoologie ;" Siebold and Kolliker: Leipzic. Yol. viii. 1856) is, 

 if possible, still more interesting, containing not merely an account of 

 several new species, but also an original method of classifying these 

 animals. His arrangement of the families and genera differs from that 

 of Professor Forbes ; and there can be no doubt that the discovery of 

 many additional forms must materially alter our views of the classifica- 

 tion of the present group. For the name Gymnophthalmata, employed 

 by Forbes, the term Craspedota is substituted. A reference to both of 

 these papers will well repay perusal. 



To revert to the British species : Forbes, in his description of the 

 Stomobrachium octocostatum, states his regret at not being able to submit 

 the specimens which he captured in 1839 to a sufficiently careful exami- 

 nation. Since that period he had never again met with it. In the summer 

 of the present year I was so fortunate as to procure a specimen of this beau- 

 tiful Acalepha. The umbrella is campanulate and convex, more pointed 

 than in Professor Forbes' figure, and so transparent that to all appearance 

 the sub-umbrella seems to form the true outline of the animal. The sub- 

 umbrella is about half the length of the umbrella, but is more depressed 

 than the latter, so as not to correspond with it in shape : it is bordered 

 by a marginal vessel and veil. The vessels are eight in number, simple, 

 of a pale-yellow tint. The ovaries were leaf-like, furbelowed, short 

 and broad, not so linear, as in Professor Forbes' s figure ; of a bright golden 

 yellow hue, very conspicuous. They were situated along the course of 

 the radiating canals, near the peduncle. This last was yellowish, nearly 

 circular, very simple, short and fimbriated. Eound the margin were 

 40 (8 x 4 + 8) tentacles, highly contracted, presenting a pilose appear- 

 ance under the microscope, springing from rather large, though not very 

 conspicuous bulbs. Between each of these was a smaller tentacle, at 

 the base of which an otolitic vesicle seemed to be placed. This Medusa 

 was nearly half an inch in length. Its favourite position seemed to be 

 when it balanced itself in the water by means of its smaller tentacles, and 

 then curved backwards, and extended the larger ones. Nothing can be 

 conceived more elegant and graceful than this posture : the tentacles 

 reached upwards to more than five times the height of the umbrella, be- 

 coming finally so delicate as to be completely invisible. 



I have no special remarks to make on the other naked-eyed Medusae ^ 



