CONGDON. — THE IIYDROIDS OF BEKMUDA. 



467 



Gencs BIMERIA S. Wright, 1859. 

 Bimeria humilis Allman. Figure 6. 



Dense growths of the colonies of this small animal are to be found 

 on Eudendrium, Pennaria, sponges, and the like. The stem of Pen- 

 naria often forms the centre of a 

 cylindrical mass a centimeter in di- 

 ameter. No gonosome is present. 



The genus Bimeria was estab- 

 lished in 1859 by Strethill Wright 

 for a hydroid of the Firth of Forth, 

 characterized by a covering of peri- 

 sarc on the hydranth body and 

 around the bases of the tentacles 

 (Allman, '71, p. 297). Allman ('77, 

 p. <S)'added to the genus the species 

 B. hv. mills from the Tortugas, which 

 differs but slightly from the Ber- 

 muda Bimeria. 



Gonosome is lacking. In two 

 respects the hydroids differ. The 

 Tortugas form has a very opaque 

 perisarc as described by Allman ; 

 in the Bermuda form it is trans- 

 parent; but descriptions of other 

 species added to the genus later by 



different authors suggest by their dissimilarity that in regard to this 

 character individuals may vary in appearance. Secondly, Allman states 

 that he was not able to detect the ends of the tentacle tubes and his 

 figures do not show them. By focussing on the end of an expanded 

 hydranth, I had no difficulty in finding them. There is thus no 

 warrant for constituting a new species unless the gonosomes reveal 

 differences. 



Figure 6. 



Colony of Bimeria humilis 

 (X 18). 



Gencs LAFOEA Lamouroux, 1812. 



Lafoea calcarata A. Agassiz. 



A small number of colonies were found growing around the base of 

 a hydroid. Unfortunately the collection was lost before it could be 

 examined at length. 



