40 PROCEEDINGS OF THE ACADEMY OF [1884. 



shape of the cup, as well as that of the body ; in the presence 

 of two lateral antennae ; in the possession of a second crop or 

 stomach situated below the ordinary crop ; in the marked muscu- 

 lar system, and in the ciliation of the net. 



The points of dissimilarity between this form and Apsilus 

 are as follows : The shape of the cup ; the absence of the gan- 

 glion ; the presence of a second stomach, and in the ciliation 

 of the cup. It differs from Gupelopagus: in the shape of 

 the cup ; in the construction of the cup ; in the two lateral 

 antennae ; in the presence of a secondary stomach ; and in the 

 ciliation of the net. 



The presence of the secondary stomach distinguishes this 

 species from the rest of the genus. The presence of cilia is not 

 so certain a distinction, as by dexterous management of illumi- 

 nation their presence might possibly be detected in some other 

 of the species. 



From the presence of the secondary stomach or pouch, it is 

 proposed to name this new species Apsilus bipera — pera meaning 

 " a little pouch to carry food." 



The reasons for uniting the three forms heretofore considered 

 separate genera, are, of course, founded on the strong points of 

 resemblance; these being, briefly, the presence of two ej^e-spots, 

 of a membraneous cup, of a mastax exactly similar in all four 

 forms, of the absence of tail or footstalk, of the absence of cara- 

 pace, and of the similar habits. 



The characteristics heretofore used in the classification of the 

 Rotatoria, as denoting members of the same genus, are : charac- 

 ter of rotatory organs ; number of e\'e-spots ; absence or presence 

 of carapace, and habits. 



In selecting the name for this new division, Dictyophora, of 

 Leidy, has the right of priority', but, owing to its having been 

 already many years in use, in two other branches of science, the 

 choice must fall upon that next in order of priority, which is 

 Apsilus, of Meczinchow. 



Tlie genus Aj^silus, then, will consist of four species — Apsilus 

 vorax Leid}'^ ; Apsilus lentiformis Meczinchow ; Apsilus buci- 

 nedax Forbes ; and Apsilus bipera Foulke. 



As there is no family in the class Rotatoria, in which the above 

 genus may be placed, a new family, to be named Apsilidse, is pro- 



