398 TUBULARID^. 



appears to be pretty much tlie same as what we find in Corymorjiha, where the thin pelHcle which 

 invests the stem becomes conspicuous near the proximal end by its separation from the ectoderm 

 at this place. It is totally different from that of the firm perisarcal sheath of other hydroids, and 

 cannot be regarded as invalidating the character of "naked" attributed to the genera of the 

 Cortjiaorplndce and MoiiocauIuJce. 



TUBULARIDjE. 



TROPHOSOME. — Hydeocaulus developed, invested by a cliitinous peeisaec, 

 Hydeanth with a proximal and a distal set of verticillate filiform tentacles. 



GONOSOME. — GoNOPHOEES in the form of fixed spoeosacs. 



TUBULARIA, Linnmis (in part). 



Name. — From tubulus, a diminiiti\'e noun formed from tuhm a pipe, in allusion to the pipe- 

 like stalks which support the hydranths. 



TROPHOSOME. — IIydeophyton consisting of a simple or branched hydeocaulus 

 and a filiform adherent nxDEOEniZA. Hxdeaxths flask-shaped, abruptly marked off 

 from the supporting stalk ; tentacles composing the proximal circlet larger than 

 those composing the distal one ; distal circlet surrounding the base of a conical 

 hypostome. 



GONOSOME. — Spoeosacs developed upon branched pedmicles, so as to form 

 racemiform clusters, which spring from the body of the hydranth between the distal 

 and proximal circlets of tentacles. Embryonal development by Actinul^. 



The genus Tiihularia of the older naturalists was an ill-assorted and heterogeneous group, 

 and at the close of the last century it still included, along with the true Tuhulance, not only other 

 hydroid genera, but various Actinozoa, Polyzoa, and certain members of the sub-kingdom 

 Annulosa. Even after it had been freed from its more glaring misassociations, it continued to be 

 imperfectly defined ; and it was reserved for Ehrenberg, in 1832, to make the first step towards a 

 reform of the group as it then stood, though from overlooking certain characters of importance 

 he failed to assign to it its natural limits as a well-defined zoological genus.' 



^ Ehreuberg, Corallenthiere, Abliandl. der Kouig. Ak. der Wessens. zu Berlin, 183,3. 



