424 HYDROLARID^. 



EcTOPLEUKA DuMOKTiERi, Van Bened. 



TuiiULARiA DuMORTiERi, — Van Beneden, Reclierches sur I'Embryogenie des Tubulaires, p. 50, 



pi. ii ; Rech. sur Fauue litt. de Belgique, p. 111. 

 EcTOPLEURA DuMORTiERi, — Aycissiz, Coiit. Nat. Hist. U. S., vol. iv, p. 343. Allman, in 



Ann. Nat. Hist, for May, 1864. Hincks, Brit. Hydr. 



Zooph., p. 124, pi. xxi, fig. 4. 



TROPHOSOME. — Htdrocaulus attaining a Leiglit of about one inch, isolated, 

 slender, simple or sliglitly ramified ; perisarc with annular constrictions. Htdranths 

 comparatively large. 



GONOSOME. — GoNOPHORES on short, erect, slightly branched peduncles. 



Hahitaf. — Attnched to Flustras, the carapaces of crabs, &c. 

 LocaJ'Uy. — Coast of Ostend, Van Beneden ; Isle of IMan, Mr. Hincks. 



I have never met with an example of the present genus, and have obtained the generic and 

 specific characters here given from M. van Beneden's description of his 'luhdaiia Dunwrtieri, 

 the only species of the genus yet discovered, at least with its trophosome. The Belgian zoologist 

 informs us that this hydroid is very abundant on the coast of Ostend, where it occurs ou Flustras 

 and Halodactylas, and on the backs of crabs, in the form of isolated stems, never forming tufted 

 masses such as we meet with in many other Tubularians. 



HYDROLARIDJ^:. 



TROPHOSOME. — Htdrocaultjs undcA^eloped. Htdranths with but two ten- 

 tacles, which are fiUform and spring from one side of the base of the hypostome ; 

 mouth with tw^o lip-like lobes. 



GONOSOME. — GoxoPHORES raedusiform planoblasts, with six simple radiating 

 canals and simple marginal tentacles. 



In the enumeration of genera on page 241 the family to which Lar has been provisionally 

 referred is named "Laridae." This name, however, cannot be retained, being already in use for 



