North American Centropagitke. 267 



species cannot belong to the genus Epischura, as has already 

 been pointed out by Forbes ('93, p. 254) and Schmeil ('98), 

 since the process cannot be homologized with the similar 

 process in Epischura proper. If, however, the process is 

 dextral, as shown in three out of the four figures published, 

 it might be more easily homologized with the process in the 

 other species of the genus. It would also be more likely that 

 the left leg was three-segmented and the right one especially 

 modified into a clasping organ if E.fluviatilis belonged to this 

 genus, although even then the fact that the second segment 

 of the left (right ?) leg is not at all produced inwardly and the 

 structure of the right (left ?) leg is radically different would 

 present difficulties. The fifth legs of the female are very 

 similar to those of Epischura, but partake slightly of the 

 characters of Heterocope. Schmeil says ('98) that, judging 

 from analogy with other genera, there is one basal segment 

 too many in the fifth pair of legs of both sexes. Herrick, in 

 the " American Naturalist" (Herrick, '83), gives a drawing of 

 a swimming leg of E.fluviatilis, with its one-segmented inner 

 ramus, which, if the upper, incomplete part shown is to be 

 regarded as another segment, certainly gives it, as Schmeil 

 says, one too many segments. If, however, it is an adhering 

 part of the thoracic segment, it will differ from a swimming 

 leg of E. lacustris only in that in lacustris the first basal seg- 

 ments instead of being fused their entire length, as in fluvia- 

 tilis, are fused for about the basal two fifths only. The fifth 

 legs of both sexes are similar in arrangement to the above, 

 although on account of the absence of an inner ramus it is 

 less evident. I believe that the appendage figured at the' 

 outer apical angle of the furca is intended for a spine, rather 

 than a seta as Schmeil supposes it to be. From this it will 

 be seen that the drawings and descriptions conflict, and Dr. 

 Schmeil was perhaps justified in proposing to establish a new 

 genus, Lamellipodia, to receive this species. It seems to me, 

 however, that it would be better to wait until material col- 

 lected in the same locality and described and figured by a 

 more careful observer has determined whether or not this 

 species is a good one, and I have hesitated, therefore, to 

 adopt a new name for a form the description of which, to use 

 Marsh's words in regard to Scopiphora vagans Pickering, " is 

 manifestly inaccurate in some particulars, and maybe in all." 



