42 BULLETIN OF THE BUREAU OF FISHERIES. 



Gemmaria cladophora A. Agassiz.™ 

 Gemmaria cladophora A. Agassiz, North American Acalephaa, 1865, p. 184. Haeckel, System der Medusen, 1879, p. 104. 



Bell subhemispherical to conical, with walls of varying thickness over different regions, 'jiving to 

 the subumbrellar cavity ;i form differing from that of the exumbrella. Marginal tentacles 4, 2 rudi- 

 mentary, the other 2 long ami abundantly supplied with batteries of nematoeysts, many of which are 

 stalked. Manubrium well developed and with the gonads borne on its proximal portion; month 

 simple, with 4 slightly everted lips, richly supplied with nematoeysts. Ontogeny unknown or doubtful. 



Colors. — Tentacles light brownish, witli orange pigmentation at the bases. 



Distribution. — Massachusetts Bay, Agassiz. Woods Hole. 



CORYNITIS McCrady (1857). 

 Corynitis a§rassizii McCrady.™ 



Coriinilis agassizii McCrady, Proceedings Elliot I Society Natural History, Vol. I. 1857, p. 132. 



Gemmaria gemmom McCrady, op. cit., p. 49. 



Zanclea gemmo&a McCrady, op. cit., ibid. 



Halocharis spiralis L. Agassiz, Contributions Natural History United states, Vol. IV, isr,2. p, 239. 



Oorynitis agassisii A. Agassiz, North American Acalephae, 1865, p. l v v Airman, Monograph Gymnoblastic Hydroids, 1871, 



p. 287; Murbach, Quarterly Journal Microscopical Science, Vol. 42, 1899, p. 354. 

 Corynelis agassizii Haeckel, System dei Medusen, 1879, p. 49. 



Bell elongate hemispherical, slightly higher than broad, about 2 mm. in height when liberated. 

 Marginal tentacles 2, long, with broad base, the entire tentacle rough with batteries of nematoeysts, 

 many of which are stalked ami erect like vorticellse, for which they might easily be mistaken upon 

 casual examination. Radial canals 4, with rather conspicuous knots of nematoeysts on the exum- 

 brellar surface of their distal ends. Manubrium well developed, flask-like, with 4 oral lips, which 

 are simple and slightly everted. 



Ontogeny. — Derived directly from the hydroid stock, easily kept in aquaria. Habitat of hydroid, 

 often on shell of MytUis, fronds of sargassum, etc. 



Distribution. — Buzzards Bay, Naushon (Agassiz); taken at docks of Fish Commission, Woods 

 Hole, July. 



LEPTOMEDUSjE. 



In contrast with the Anthomedusse, the Leptomedusae are usually characterized by a flatter 

 and more disk-like umbrella, which is also often of mote delicate texture, or thinner and softer; the 

 velum is usually less developed; tentacles usually more numerous and with a more general disposition 

 about the margin. Gonads almost always home upon the radial canals. Ocelli may or may not be 

 present; sensory bodies usually of the vesiculate type — otocysts. 



Tu.u'MANTimiE. — Radial canals 4 or *; rarely more, always simple and unbranched. Tentacles 

 usually numerous: ocelli usually present, otocysts usually lacking; manubrium usually short, with 

 4- to 8-lobed mouth; gonads in the form of undulating band-like organs along the radial canals. 



Cannotid.e. — Radial canals 4 or <i, branched or with lateral pinnate diverticula; tentacles usually 

 very numerous; ocelli usually present, otocysts lacking; gonads usually spindle-like pouches on the 

 radial canals; mouth with 4 or 6 oral lobes, which are sometimes rudimentary. 



Eucopidje. — Radial canals always 4, simple and unbranched; tentacles usually numerous, at leasl 

 4; manubrium usually short and quadrate in section, with 4 oral lobes; ocelli absent, otocysts always 

 present, usually s or more; gonads usually vesiculate bodies on the radial canals. 



JEquoreid.e. — Radial canals numerous, 8 to 16 or more, often 100, simple; tentacles at least s. 

 usually very numerous; otocysts always present, 8 or more; ocelli absent; gonads usually ribbon-like; 

 manubrium varying from very short to long, oral lobes usually numerous and variously plaited or 

 folded. 



« In a forthcoming paper i Mittheilungen Zoolischen station Neapel, Bd. It;, 1904, s. 550), on sonic Hydromedusse from 

 the Bay of Naples, the present writer has taken occasion to express decided doubt as to tin- generic distinctness of these 

 medusa?. It would seem more correct to regard them as related species 



