80 



U.S. NATIONAL MUSEUM BULLETIN 260 



palm of giiathopod 1. Schisturella zopa has a transverse palm on 

 gnathopod 1 and an adze-sliaped anteroventral extension of 

 epimeron 1. 



Figure 37. — Schisturella iotorami, new species, male, 5.9 mm, Santa Monica Bay, Calif., 

 183 m: a, maxilla 1, aboral; h, maxilla 2; c, outer plate of maxilla 1, oral; d, inner ramus 

 of uropod 2; ej, mandibles; g, maxilliped; h,i, left and right mandibular molars; /, lower 

 lip (part). 



Tmetonyx Stebbing 



Tmetonyx Stebbing, 1906, p. 73. 



Remarks. — J. L. Barnard (1962a) synonymized Tmetonyx Steb- 

 bing with TrypJiosa Boeck, but the type-species of the latter is synony- 

 mous with Orchomene even though the remaining species of '"'•Try- 

 jylioscC^ are not. In view of the normal first coxa of the type-species 

 of Tmetonyx^ Oniscus cicada O. Fabricius, and the tapering first coxae 

 of other species of Tmetonyx and those of '''•Trypliosa''' auct., it might 

 have been wiser to remove from Tmetonyx all species except the type 

 and assign them to '"''Tryphosa'''' auct. ( = TrypJiosella Bonnier) . Two 

 subgenera within '•'•Trypliosa''' might have to be established in recog- 

 nition of the presence or absence of a dactylar tooth on gnathopod 

 1. In this way one might hypothesize that ancestors like Tmetonyx 

 cicada gave rise to members of ^''Trypliosa''' through reduction of coxa 

 1, and that some of these, through loss of the dactylar tooth, gave rise 

 to the members of the second "subgenus" of '"'"TrypTiosaP The alter- 



