the Genus Cynioiioniop3. 573 



between and beyond which can be seen, in a dorsal view, the 

 roof of tlie much-prodnccd efferent branchial canal. On 

 either side of the rostrum are two teeth which form the 

 dorso-lateral walls of the common orbito-antennnlar fossae. 



The eye-stalks are slender and freely movable ; the eyes 

 are almost without pigment. 



The antennules, which are larger than the antennae, are not 

 entirely concealed in flexion. 



The buccal cavern is of great length, its median efferent 

 branchial canal, which is remarkably well defined, being 

 prolonged anteriorly over the epistome and beyond the 

 ro>trum; it is closed ventral ly and anteriorly, except as 

 regards the tip of the branchial canal, by the long narrow 

 external maxillipeds. 



In the external maxillipeds the merus is about three fourths 

 the length of the ischium, the flugellum (which is coaipletely 

 expo'^ed) articulates near the middle of the merus and well 

 inside its edge, the exopodite (which is broad and non- 

 flagellate) is hardly longer than the ischium, and the epipoilite 

 is absent or minutely vestigial. 



In the first maxillipeds the endopodite is nearly twice as 

 long as the exopodite and is produced as far as the end of 

 the efferent branchial canal, to which it forms a floor, as in 

 typical Oxystomes ; and the epipodite is large and foliaceous. 



In the second maxillipeds the exopodite has the form of a 

 lash and is much longer than the endopodite, and the epipo- 

 dite also is of great length. 



No afi'erent branchial fissnre is visible between the carapace 

 and the base of the chelipeds. 



The chelipeds are ecptal and arc much shorter, and in both 

 sexes much stouter, than the legs. 



The first and second pairs ol true legs are stouli>h and arc 

 of very great length, especially as regards the merus. The 

 third and fourth pairs of legs are short, almost fihimentous, 

 and have the usual dorsal elevation. 



The abdomen in the male is small, is not so broad as the 

 corresponding part of the thoracic sternum, and carries two 

 pairs of large appendages modified for sexual purposes; in 

 the female it is large and broad and carries four pairs of 

 ap[)en(lages ; in both sexes only six segments are distin- 

 guishable. 



The oviducts open on the coxa3 of the second pair of true 



legs- 



The branchial formula is as follows : — , 



