254 



concave, thickened, prolnuling, proximal rim, has two well-developed, conspicuous 

 hinge-teetli and is closed finally hj' tlirce (one distal and two proximal) calcareous 

 processes, springing from its inner margin and meeting in the centre. The pedal 

 chambers, at any rale those of the single zooecia and the molher-/o(iL'cia, are very 

 long, narrow and their frontal wall is cpiite uncalcified. 



The peculiar occlusion we lind in this genus is similar to that in Mclicertites 

 Roiiana pointed oul by \\'alers'. Here also il is brought about by means of 

 3 — 4 calcareous processes, which meet in the cenlie of the aperture. If there are 

 three, which is usually the case, they are however di.sposed in a dill'crent way 

 from in the species of the genus Calenaria, as in the above species theie are two 

 distal and one proximal. The type-species of this genus is C<d. Conlci And., of 

 which Mr. Waters- has recently given a description. 



Catenaria formosa Husk. 



Catenicella formosa Busk, Voyage of Rattlesnake, I, pag. ;(()(), Catalogue of Marine 



Polyzoa, Cheilo.stomata, pag. 9, PI. VII, ligs. 1, 2. 



(IM. XXI, li{^. 3 a, I'l. XIIl, lig. 2 a). 



The zooecia, the breadth of which may be contained l'/2 times in the length, 

 are of a robust, angularly oval form, and the boundary between the flat frontal 

 wall and the arched basal wall is formed on either side by a distinct marginal 

 ridge. The aperture is provided with a proximal, strongly concave margin. 



The lateral chambers. The scapular chamber, which in most zooecia seems 

 to be developed as an avicularium with a small mandible, is large, compressed, 

 somewhat ascending and protruding almost straight outwards, being only slightly 

 inclined frontally. The supra-scapular chamber is a low, narrow cavity, provided 

 with a membranous roof in the whole of its length. The infra-scapular chamber 

 is a small, wholly frontal cavity with a circular opening, through the centre of 

 which the septum between the zocrcium and the avicularium can be seen; and 

 the pedal chamber, which attains an unusually large breadth, though but seldom 

 more than half the length of the zocrcium, is likewise frontal and has its start- 

 ing point somewhat i)roximally to the opening of the infra-scapular chamber. It 

 is considerably smaller on the daughter-zooccium than on the other zoo'cia and 

 especially very small and oval on its adzonecial side. In the bizotrcial joint we 

 find a pear-shaped or oval boundary chamber (m. III). The adzoircial side of 

 the daughter-zoa'cium is generally i)rovide(l with an avicularium and the ad- 



' 108 ;i, p. .52. ■-' ll(!,i, p. 130. 



