C. F. ROUSSELET ON RATTULUS COLLARIS. 269 



segment of the foot to which they are jointed, and which is 

 not wrinkled ; this segment again telescopes into the preceding 

 portion of the foot, which after that becomes wrinkled. The 

 whole foot can be withdrawn inside the lorica, and in life is 

 generally so carried by the animal when swimming. In the 

 majority of the species of Brachionus the toes are conical, with 

 a minute opening at the very tip of the cone, but in Brachionus 

 angularis the toes have a very similar structure to those of 

 Schizocerca, except, of course, that they are not so long ; they 

 are shouldered, that is, drawn out on the outer side into a thin 

 fleshy " toe-nail "-like structure, at the base of which the foot- 

 gland opening is situated. This structure of the toes of B. 

 angularis seems to have escaped Dr. Hudson and Mr. Gosse, 

 although Dr. Plate's drawing in 1885 of B. bidens, which is the 

 same species, shows it quite distinctly, and he mentions it in 

 the text. It will be seen therefore that the peculiar structure 

 of the foot and toes of Schizocerca is hardly of sufficient im- 

 portance to justify the formation of a new genus for its 

 reception. In a recent paper on Syrian Rotifers Dr. Daday 

 and Dr. Barrois figure an empty lorica under the name 

 Brachionus caudatus, n. sp., which has the greatest possible 

 resemblance to Schizocerca, except that the two large frontal 

 spines are quite absent, and the posterior spines only half as 

 long as those of Schizocerca. 



I will not omit to mention that Dr. Hudson's summary of 

 the generic characters of Schizocerca, given in the supplement 

 to the Rotifera, as follows : " With a long foot ending in a 

 fork of two unequal branches, each terminated by a pair of 

 unequal toes," is not quite correct, and is based on Dr. Daday's 

 tigure, which certainly shows such characters, but in his Latin 

 diagnosis of the species he mentions only that the toes are un* 

 equal, not the branches of the fork. 



Size: Length of lorica, including the spines, ^ 5 in. (0"39 mm.). 



A mounted slide of Schizocerca diver sir omis will also be 

 placed in the collection of the Club, and here again I am 

 indebted to Mr. F. R. Dixon-Nuttall for the accurate figures of 

 this animal reproduced in the plate. 



