232 The Microscope. 



Length of zooid, g^i^^ to ^J-^ of an inch. On Gammarus and 

 Entomostraca. 



I have often observed this species fairly clothing the antennae 

 of Gammarus, and in large numbers on smaller Crustacea. The 

 inconspicuous collar and moderately elevated disc give the species 

 decidedly the appearance of an Epistylis. It can not be easily mis- 

 taken for any other opercularian. 



Lagenophrys vaginicola, Stein. This species is attached to 

 Canthocamptus -minutus. I have found an abundance of a form on 

 this entomostracan which heretofore has been regarded as identical 

 with the European animal. During the months of April and May 

 just passed, many were examined and compared with Stein's figures 

 and description, and ours differs constantly in the form of the lorica, 

 viz : the lorica is not cordate, but a plain ovate, the length is equal 

 to or greater than twice the width, and the aperture is not circular 

 but oblong, closed as described by semicircular, prominent valves ; 

 the size of this variety is larger than the cordate one ; the lorica is 

 striate, like that of cothurnia lata, although not so easily made out; 

 again, the examples are not always adnate, but attached by the pos- 

 terior extremity, so that the lorica is free except the then attenuate 

 extremity. I propose for our variety L. vaginicola variety ovata. 



As the season advanced, a supposed cystic stage was frequently 

 observed. This occurs loosely within the lorica ; it is sphei'ical in 

 form and surrounded by short, radiating spines. 



The species of Lagenophrys, thus far figured, are circular when 

 seen from above, except the species and variety already mentioned : 

 and when seen from the side are plano-convex. There occurs 

 rarely oa Cypris, a species which is not plano-convex in side-view, 

 but nearly rectangular, i. e., the plano-convex type flattened, the 

 upper surface being nearly plain, and parallel with the adnate surface. 

 The animal nearly fills the lorica and protrudes its disc through a 

 short tube closed by lip-like lids. I propose to call it, provisionally, 

 Lagenophrys discoidea. The width of lorica is -^^-^ of an inch. From 

 a swamp at Point Abino, Ontario. I hope to find it again during 

 the present summer, and study it sufficiently to enable me to decide 

 whether it is a distinct form or a variety of some other now known. 



Is it Gerda or OpJirydium f I recently obtained fi*om Lime 

 lake, a few miles south of Buffalo, a number of social groups of a 

 species re.sembling what I have elsewhere described* as Gerda 



* Proc. A. S. M. vii.-44. 



