98 MARINE POLYZOA. 



and as one of the subdivisions for which he proposed the name 

 Cupularia coincides with the one of those into which I believe 

 it naturally falls, that name has been retained. The same divi- 

 sion of the genus Lunulites, as originally constituted, is suggested 

 by Mr. Lonsdale's observations with respect to Lunulites denti- 

 culata (1. c. p. 503), and it is consequently sufficiently apparent 

 that the generic divisions here adopted will apply equally to fossil 

 and to recent forms. The examination of the former alone, 

 however, would never have led to the proper appreciation of the 

 characters here employed, because, from fossil specimens, it was 

 impossible to arrive at any satisfactory elucidation of the respect- 

 ive nature of the two kinds of cells. Mr. Lonsdale hints (/. c. 

 p. 504) that the secondary pores or small chambers in the quin- 

 cuncial species offer a perfect analogy with the chambers in 

 Eschara and Escharina, " supposed to be receptacles for matu- 

 ring gemmules ; " but in this, as I have fully ascertained from 

 the examination of numerous recent species, he is mistaken. 

 The secondary chambers are the cells of vibracula, and in the 

 living state contain probably nothing but the muscular apparatus 

 for the movement of a very long and strong vibracular organ. 

 Where the true ovicells are, if such organs exist in this family, 

 I have been unable to perceive ; but that the smaller cells in 

 question are of the nature I have mentioned will be sufficiently 

 obvious on inspection of almost any of the figures here given. 

 As the present part of this Catalogue is limited to recent species, 

 no mention is here made of fossil ones, of which a future op- 

 portunity will be taken to speak. 



To facilitate the description of the species, it will be as well to 

 define certain terms, which it is convenient to employ. 



1 . Area of cell means the space occupied by the front of each 

 cell, which is bounded by a raised line. 



2. Lamina is the calcareous expansion which partially forms 

 the anterior wall of the cell, the rest being occupied by a mem- 

 branaceous or horny layer, as in Membranipora. 



3. Aperture is the opening or space thus left unfilled by the 

 calcareous lamina, in the upper end of which, or that furthest 

 from the centre of the polyzoary, is the true mouth, with the 

 moveable lip, which is for the most part removed with the horny 

 layer. 



4. Vibracular opening is the opening of the cell containing 

 the muscles for the movement of the vibraculum. 



1. CUPULARIA GUINEENSIS, n. s. PI. CXIV. 



Polyzoary orbicular, in section crescentic ; area of cell rhom- 

 boidal, aperture ovoid, lamina granular ; vibracular opening au- 



