66 CANADIAN FOSSILS. 



Genus Maloctstites, Billings. 



Generic Characters. — Body ovate or globular, composed of an 

 indefinite number of plates, usually about forty or fifty ; mouth, 

 almost apical; ambulacral orifice on one side, but in the upper half 

 of the body ; arms recumbent, in some species numerous ; plates 

 thick solid, not poriferous ; column unknown. Generic name from 

 malum, an apple. 



This genus is composed of some species of Cystideans lately 

 discovered in the Chazy limestone. They are usually globular, and 

 covered with smooth plates, and in general form and aspect much 

 resemble the Echinospheerites of Scandinavia and Russia, from all of 

 which however they differ in the absence of pores in their plates. 



The genus Cryptocrinites (Von Buch) is related to Malocystites so 

 far as regards the absence of pores or pectinated rhombs, but differs 

 in having the ambulacral orifice in the apex, the mouth being in the 

 side, and appears to be composed of a definite number of plates, there 

 being three in the basal series, five in the second series, and alter- 

 nating with these, five others in the second series. 



Malocystites differs from Amygdalocystites in being composed of a 

 lesser number of plates, and in having the ambulacral orifice in the 

 side, and the mouth nearly in the centre of the apex. The arms 

 appear also not to be alike in the two genera, although none of 

 the specimens are sufficiently well-preserved to shew the structure 

 very distinctly. 



XIV. Malocystites Murchisoni, Billings. 

 Plate VII. Figs, la—li. 



Description. — Body globular, or slightly ovate ; plates varying 

 from plane to convex, covered with small granular tubercles ; arms 

 usually eight, forming two fascicles of four in each, connected by a 

 short groove, in the bottom of which is the ambulacral orifice ; 

 they are long, and wind around the body obliquely descending from 

 the orifice nearly to the base ; mouth nearly circular, without valves. 

 In a specimen eleven lines long and ten lines in greatest breadth 

 the ambulacral orifice is half a line broad, and the mouth one line 

 and a half. The area of the mouth is therefore about nine times 

 o-reater than that of the ambulacral orifice. 



