286 CORYNITIS. 



more than an inch in polar diameter," is very full, and is accompanied by a figure. He o-ives 

 no figure, however, of the trophosome, and his description of it is hardly detailed enough for a 

 sufficiently distinctive diagnosis, while he adduces no evidence to connect with it the free- 

 swimniinK medusa. 



COEYNITIS, M'Cradf. 



Name. — From Kopmn], a club, in allusion to the club-shaped hydranths. 

 Halocharis, Agassiz. 



TROPHOSOME. — Hydrocaulus absent, so lliat the hydrautlis are sessile on tlie 

 iixDRORHizA.^ Hydranths cylindroid. 



GONOSOME. — Planoblasts springing from the hydranth. Medusa (wlien fully deve- 

 loped) having a deep umbrella ; manubrium massive, and destitute of oral tentacles ; 

 marginal tentacles four, each with a clavate extremity and with an ocellus on the 

 bulbous base ; roof of umbrella cavity rising in four overarched spaces, between the 

 roots of the radiating canals. 



The trophosome of the present genus was described and figured by Agassiz xmder the name 

 of Halocharis." He was unacquainted, however, with the gonosome, and he shortly afterwards 

 changed this name to that of Corynitis, for he found that his Halocharis was identical with 

 Corynitis, a genus which had been previously instituted by M'Crady' for a liydroid, whose 

 gonosome, as well as trophosome, had been examined by this naturalist.* 



The genus Corynitis comes very near to Syncoryne, from which it is separated chiefly by 

 the undeveloped or rudimentary hydrocaulus, and to Gymnocoryne, so far, at least, as its 

 trophosome is concerned, for the gonosome of Gymnocoryne has not yet been discovered. From 

 the last-named genus Corynitis is distinguised mainly by the fact that its distal tentacles do not 

 form a distinctly defined verticil. 



' This character is adopted from Agassiz's description ; it is highly probable, however, that a 

 rudimental hydrocaulus will be found to e.'cist as in Clava. 



- 'Contrib. Nat. Hist. U.S.,' vol. iv, p. 239, pi. xx, f. 10. 



^ McCrad}', ' Gymnoph.,' p. 131. 



* It is true that the name of CorijnUis had been already used by the botanist, for Sprengel had 

 employed it to designate a genus of Leguminosce. The Coryyiiiis of Sprengel, however, is synonymous 

 with Coronella, De Cand., and as this name has precedence in point of publication, Corynitis must 

 give way to it, and becomes thus freed for appropriation by the zoologist. 



