yg^ CRUSTACEA. 



either side produced backward considerably; first segment of abdomen 

 as long as three preceding thoracic segments. Inner caudal lamella 

 somewhat denticulate on outer margin. 



Cassidina latisttlis. 



Corpus sat angustum, multum convexum. Caput paulo transversum. 

 Segmenta thoracis 2-7 subcequa. Abdominis segmentum ultimum 

 parce brevius quam latum, extremitate latl rotundatum, truncatum. 

 Styli caudales abdomen paulo superantes, lamelld interna, perlatd, sub- 

 triangulatd, extremitate obliqud truncatd, externd parvuld oblongo- 

 ovatd, subacuminatd, triplo brevwre et plus triplo angustwre quam 

 interna. 



Body rather narrow, much convex. Head somewhat transverse. 

 Segments of thorax from second to seventh subequal. Abdomen 

 sparingly shorter than broad, broadly rounded at extremity, and 

 truncate. Caudal stylets extending a little beyond line of abdomen, 

 inner lamella very broad, subtriangular, extremity oblique truncate ; 

 outer oblong-ovate, subacuminate, quite small, one-third the length 

 and less than one-third the breadth of the inner lamella. 



Plate 52, fig. 12 a, animal, enlarged two diameters ; b, under view 

 of abdomen ; c, upper view of caudal appendage ; d, under view of 

 head, showing mouth, antennae, and anterior legs (except part of the 

 leg on the right in the figure) ; e, extremity of leg of fourth pair. 



Locality doubtful. 



Length of body, six and a half lines ; breadth, three lines. The 

 front has nearly the same outline as in Amphoroidea. A median 

 process extends downward between the bases of the superior an- 

 tennae, which bases are rather broad. The legs are very nearly 

 naked ; the tarsus of the different legs has a small spine beneath the 

 terminal claw. The first antennae are about two-thirds as long as the 

 second, and the flagellum of the latter has seventeen or eighteen 

 joints. 



