CRYPTOLARIA LONGITHECA. 19 



merely a parasitic hydroid we should have in these bodies a gonosome 

 without its correlative trophosome. Further, the tubular base from which 

 the gonangia spring forms a close irregular plexus which embraces the fas- 

 cicled stem of the supporting hydroid, and 1 believe I have traced a com- 

 munication between this plexus and the cavities of the outermost tubes of 

 the stem. 



If we admit the reasonableness of this view, we may compare the entire 

 hydroid to a Coppinia in which the trophosome, instead of consisting of 

 a number of sessile hydrothecse intercalated among the gonangia of the 

 gonosome, as in the only known species of Coppinia, is further differentiated, 

 and assumes the form of a branching hydrocaulus with the hydrothecte 

 distributed along its length. 



I do not wish, however, to lay too much stress on this view. I do not 

 feel that I have been able to place beyond all doubt the reality of a com- 

 munication between the tubular base of the incrusting body and the tubes 

 of the stem, while the fascicled condition of the stem increases the difficulty. 

 Against its constituting the proper gonosome of the supporting hydroid, 

 may also be urged the facts of its irregular form and of its sometimes ex- 

 tending in such a way as to embrace a portion of more than one branch, 

 exactly as a foreign incrusting growth might do. The question, however, 

 of its exact relation to its associated hydroid must await for its solution 

 the examination of recent specimens. 



Cryptolaria longitheca. 



PI. .XIII Figs. 4, 5. 



Trophosome. — Hydrocaulus attaining a height of about two inches, pin- 

 nately but not profusely branched; fasciculation disappearing towards the 

 ends of the branches. Hydrothecfe cylindrical, adnate in the non-fascicled 

 portion for about half their height, then becoming free and bending out- 

 wards ; margin circular and even, surrounded by annular striae. 



Gonosome not known. 



Dredged off Double-Headed Shot Key from a depth of 315 fathoms. 



Cryptohria longilheca is a fiir less profusely branched species than C. conferta, 

 and from this species it further differs in the pinnate disposition of its 

 branches and in being a stronger form with larger hydrothecaj. The hy- 

 drothecJB, moreover, where a complete view of them can be obtained, as in 



