CYMOTHOIDEA. 733 



Plate 52, fig. 10a, animal, magnified six diameters; b, part of fla- 

 gellum of second antennae; c, antenna of first pair; d, margin of seg- 

 ments of thorax, much enlarged. 



Harbour of Rio de Janeiro; caught in the cavities among Balani, 

 on the shores of Rat Island. 



Length, one-fifth of an inch. Colour of head, light greenish yellow, 

 a central longitudinal line along thorax of same colour, which widens 

 near the middle of the body; other parts deep brown, with some light 

 spots. Colours sometimes faint. 



. 



Spheroma Dumertiii, Audouin, Explic. des planches de M. Savigny, Egypte, pi. 12, 



Spheroma Savignii, Edwards, Crust., iii. 208. 



Spheroma ORIENTALIS. 



Corpus fere Iceve. Segmentum abdominis ultimum subtriangulatum, 

 twnidum, dimidio vel tertio dor si postico subito depresso, extremitate 

 emarginato, emarginatione rectangulatd, latiore quam pro/undiore. 

 Appendices caudales laterales ciliatw, extremitatem abdominis paulo 

 mperantes, externa acuta, internd apice emarginatd. 



Body nearly smooth. Last segment of abdomen subtriangular in* out- 

 line, tumid. Posterior half or third abruptly depressed, extremity 

 bidentate, the emargination rectangular, broader than deep. Caudal 

 appendages ciliate, extending a little beyond extremity of abdomen, 

 outer acute ; inner emarginate or bidentate at apex. 



Plate 52, fig. 11 a, body, much enlarged ; b, part of leg of one of 

 three posterior pairs; c, lateral profile of abdomen, upper side, showing 

 the abrupt depression of posterior part ; d, under view. 



Singapore. 



Length of body, one and a half to two lines. The tarsus of the six 

 posterior legs has a prominent spine or tooth on under side; preceding 

 joints nearly naked, a spinule at lower apex. Segments of thorax 



