MARINE POLYZOA. 



Fam. 1. CATENICELLID^E. 

 Cells connected by flexible joints. 

 Catenicellidae, Busk, Voy. of Rattlesn. i. 352. 



Synopsis of Genera. 



1. Catenicella. 



2. Alysidium. 



3. Calpidium. 



I. CATENICELLA. 



Cells arising one from the upper and back part of another by a 

 short corneous tube, all facing the same way, and forming dicho- 

 tomously divided branches, of an erect phytoid polyzoary ; cell 

 at each bifurcation geminate ; each cell with two lateral processes 

 usually supporting an avicularium. Ovicells either subglobose 

 and terminal, or galeriform, and placed below the opening of a 

 cell in front. 



Catenicella, p., Blainvitte, Man. d'Act. 

 Catenaria, Savigny, Egypt, pi. 13. 



It is much to be regretted that no observations have hitherto 

 been made upon the living animal in this genus, which might 

 almost be regarded as the type of the suborder to which it be- 

 longs ; and it is to be hoped that future observers, in the Austra- 

 lian seas, will make the various species of Catenicella the subject 

 of assiduous study. Considerable light will thence be derived as 

 to the nature and relations of the Polyzoa, thus studied in their 

 simplest, but at the same time perhaps most perfect form. 



The genus may be regarded as characteristic of the Australian 

 seas; for although it occurs elsewhere in the southern hemisphere, 

 it does so but rarely, and it is almost unknown in the northern 

 hemisphere. Of the seventeen species enumerated below, thir- 

 teen were collected on the coasts of Australia and New Guinea, 

 on the voyage of H.M.S. Rattlesnake. Several of these, and 

 some other species which do not occur in the Rattlesnake col- 

 lection, are found in New Zealand and Campbell's Island. Two 

 or three other species, one at least common to Australia, occur in 

 South Africa. 



A species, undoubtedly referrible to this genus, is figured 

 by Savigny (Egypt, pi. 13. fig. 1) under the name of Catenaria, 

 and described by Audouin under that of Eucratea contei. The 

 characters, however, given of this species, either in the figure or 

 description, are insufficient for its exact determination among 

 such a number of forms, greatly resembling each other in gene- 

 ral aspect : and although the Cellaria catenulata of Lamarck (An. 



B 2 



