GENUS HUXLEY A. 757 



the left ; a movable stylate appendage attached to the posterior extremity ; 

 cilia confined to a subcentral, curved, band-like area of the ventral surface ; 

 oral aperture opening on the anterior half of the body, supplemented by a 

 simple horny tubular pharynx, a single long, stiff cilium or seta projecting 

 externally from the oral fossa. HAB. Salt and fresh water. 



Trochilia palustris, Stein. PL. XLII. FIGS. 51 AND 52. 



Body ovate, gibbous, its breadth equal to about two-thirds of its total 

 length, the anterior extremity obliquely truncate, curved towards the left, 

 the stylate caudal appendage equal to one-third of the length of the 

 body, directed towards the left side ; the central ciliated band following the 

 curvature of the right side of the body, slightly widest at the anterior end, 

 and gradually tapering towards the posterior extremity ; endoplast oval, 

 situated towards the centre of the left side ; contractile vesicle single, 

 spherical, occupying a similar position on the right-hand border. Length 

 of body 1-750". HAB. Freshwater. 



A species having only about half the dimensions of T. palustris, but otherwise 

 resembling it, has been described by Wrzesniowski under the title of T. polonica. 



Trochilia sigmoides, Duj. PL. XLII. FIGS. 47 AND 48. 



Body ovate, the posterior extremity rounded, the anterior one pointed, 

 curved towards the left ; the dorsal surface of the carapace ornamented with 

 five or six conspicuous longitudinal, somewhat oblique ribs or flutings. 

 Length of body i-i 150". HAB. Salt water. 



The Huxleya sulcata of Claparede and Lachmanni s identified by Stein with 

 this form, and a comparison of the original figure and description of the type given 

 by Dujardin with that of the more recent Swiss authorities, here reproduced, would 

 seem to justify the endorsement of Stein's conclusions. 



Trochilia marina, Meresch. 



Body oval, slightly compressed ; dorsal surface ornamented with two 

 grooves which extend throughout the entire length of the body. Length 

 1-750". HAB. Salt water : Black Sea (Mereschkowsky). 



GENUS VI. HUXLEYA, C. & L. 



Animalcules free-swimming, persistent in form, but not encuirassed, 

 more or less ovate or subcylindrical, having a narrow entirely ciliate ventral 

 furrow, and a posteriorly developed caudal style ; no anteriorly projecting 

 oral seta. 



As first pointed out by Stein, the Huxleya sulcata of Claparede and Lachmann is 

 synonymous with the Trochilia sigmoides of Dujardin. The Huxleya crassa of the 

 same authorities is, however, an animalcule exhibiting structural differences 

 sufficient to permit of its being retained as the type of a distinct genus, and 

 simultaneously of rescuing from extinction a world-honoured title that must otherwise 



