OF WESTEKN SIND. 65 



The periproct is high up, oval in the longitudinal direction, and has a faint groove 

 below it on the sloping truncation. 



The length of the test of one specimen is -^^ inch, breadth t% inch, and height 

 1% inch. A larger specimen is in length -^ inch, breadth -^ inch, and height 

 ^0 inch. 



Localities. From hills east of Lynyan, Eanikot series (Survey-number G f-fe) ; 

 and north-east of Band Vero in the same group (Survey-number G xf^). 



Illustrations of the Species in Plate XVII. 



Fig. 5. A large specimen, side view: natural size. 



6. A smaller specimen (the type), side view : natural size. 



7. The same, from behind : natural size. 



8. The apical region : magnified. 



9. The peristome : magnified. 

 10. Ornamentation: magnified. 



Remarks. Although the shape of the test of this species is very abnormal for 

 Echinanthus, we consider that the essential characters of its structure are naturally 

 referable to i.hat genus, of which, however, it will stand as a very extreme form. It is 

 readily distinguishable from any of the species hitherto described. 



Genus CASSIDULUS, Lamarck, 1801. 



Test of small or moderate size, oblong, convex above, flat beneath, or slightly 

 depressed along the median longitudinal line. 



Apical system slightly eccentric in front. 



Ambulacra short and very petaloid. Pores conjugate, the external series more 

 elongate than the internal. 



Peristome subpentagonal, more or less eccentric in front, surrounded with a well- 

 developed floscelle. 



Periproct oval, longitudinal, supero-marginal, placed at the commencement of a 

 short groove which does not indent the margin. 



Tubercles small and uniform on the abactinal surface, but much larger on the 

 actinal surface, excepting along a median longitudinal band. 



1. Cassidulus ellipticus, sp. nov. Plate XV, Figs. 7-10. 



The test is long, depressed, elliptical in marginal outline, longer than broad, nearly 

 twice as broad as high, slightly broadest behind the peristome, flat below, with a very 

 slight downward projection of the posterior end, which is truncated for a short distance 

 in the median line. The margin is rounded and tumid in front, and less so and more 

 sharp at the sides and posteriorly. Above, the test is very regularly convex in trans- 

 verse outline. The longitudinal outline is rather flat behind the slightly eccentric-in- 

 front apical system ; there is a faint keel, and then a sudden fall and a sharp slope 

 to the margin. In front the slope is more gradual and faintly curved to the more 



