34 CELLULARinXE. 



with vibracula; they seem still to retain some obscure 

 traces of these organs. In the latter the claspers or 

 tendril-like fibres originate (in some cases at least) from 

 a small swelling on the upper part of the zooccium, 

 which occupies the usual position of the vibracular cell, 

 and is probably the remains of one. In the present 

 genus it is represented by a simple pore, from which the 

 radical fibres proceed. 



CELLULARIA PEACHII, Busk. 



Plate V. figs. 2-5. 



CELLULARIA PEACHII, Busk, Ann. N. H. (2nd ser.) vii. 82, pi. viii. figs. 

 1-4; B. M. Oat. i. 20, pi. xxvii. figs. 3, 4, 5 : Smiff, 

 Kritisk Forteckn., (Efyers. af Kongl. Vetensk.-Akad. For- 

 handl. 1867, no. 5, 285 & 322, pi. xvii. figs. 51-53. 



CELLCLARIA NERITINA, var., Johnst. B. Z. 340 (teste Busk). 



BUGULA NERITINA, var. b, c, d, e, Gray, B. M. Oat. Radiata, 114. 



Zoarium white and glossy, dichotomously branched, 

 forming slender phytoid tufts. Zoaecia biserial, alter- 

 nate, elongate, attenuated downwards, with a small 

 spine on the upper and outer angles, frequently 

 wanting; aperture oval, sometimes much lengthened, 

 and narrowed below, occupying about two thirds of 

 the front of the cell > margin thickened slightly, and 

 minutely granular; dorsal surface smooth, with 3-5 

 perforations ; commonly a spine on the summit of the 

 median cell at each bifurcation. Oaecia subglobose, 

 surface tessellated. 



RANGE OF VARIATION. The cells are more or less produced 

 below ; and the shape of the aperture varies from a pretty 

 regular oval to an elongated form, narrowed towards the 

 bottom. The granulated margin is not always present ; 

 and the marginal spine is very frequently wanting. 



