HARDWICKE'S SCIENCE-GOSSIP. 



273 



very delicate horn-like pieces, apparently connected 

 with the teeth of the mastax, which may be seen to 

 open and close as though biting. It is probable, that 

 their function is auxiliary to that of the jaws proper, 

 but their motion is, I think, independent of these. 

 That small area of the ventral surface, which I call 

 the^hinge-plate, is of unusual form. Dilating above 

 the usual blunt point to about the normal width, it 

 thence narrows to a blunt anterior point, having thus 

 ihe outline of a spear-head. So far as I can make 



Fig. 157. — Distyla clnra : a, dorsal view : b, hinge-plate ; 

 c, toe, lateral aspect. X 640 diam. 



out, the foot is in no way attached to the shield- 

 plate. I have never seen the creature assume the 

 retracted position, even in death. It will withdraw 

 the corona and partially retract the head, but that 

 appears to be all, and is done only for the briefest 

 periods. The lorica seems to be only stiff enough to 

 constantly assume the outline shown and the dorsal 

 plate is distinctly and gracefully arched. Quite 

 devoid of markings or folds, it is extremely tran- 

 sparent and delicate. I never find empty loricce, 

 and conclude that these decay as quickly as the soft 

 internal parts. 



The animal, although always on the alert, is 

 quieter and more sedate in its habits than some of its 



relatives, and it swims readily enough in a steady 

 manner. 



The species was fairly plentiful in sphagnum, 

 gathered last August at Sandown (I.W.), but I 



Fig. 15S. — Mouostyla galeata, ventral view. X 575 dbm. 



A 



Fig. 159. — Distyla. agilis : a, dorsal view; b, ditto, retracted; 

 c, hinge-plate. X 520 diam. < 



have not yet met with it elsewhere. Length, about 

 rfc inch. 



Distyla agilis, n. sp. 



Sp. Ch. — Small but of elongate form ; lorica 

 membranous throughout. Anterior margins gaping 



