African Crustacea. 243 



Gen. XEINOSTOMA, uov. 



Carapace orbicular, rostral process broad, arched, produced beyond 

 the orbits. Pleon in both sexes consisting of six segments, of which 

 the first and sixth are much the narrowest. Eye-stalks of moderate 

 length, slightly bent. Palp of mandibles three-jointed. First 

 maxillae having a long spine-like termination to the palp. Second 

 maxillae feebly developed except as to the vibratory lamina. First 

 maxillipeds with first joint small, second narrow at apex, rest of endopod 

 broadly produced beyond the exopod to a squared apex ; exopod with 

 a small one-jointed flagellum.. Second maxillipeds having the terminal 

 joint of the eudopod attached in cheliform fashion 011 the inner side of 

 the penultimate, the long nan-ow exopod ending in a small one-jointed 

 flagellum. Third maxillipeds reaching beyond the broad front of the 

 buccal frame, the exopod not concealed, a very elongate oval, with no 

 flagellum, the fourth joint of the eudopod considerably shorter than 

 the third but fully as broad, approaching a semicircle in shape, with 

 the fifth joint attached below the apex of the inner margin. The 

 chelipeds denticulate, stouter than the setose second and third per- 

 aeopods. The fourth and fifth peraeopods very slender, subdorsal. 

 The generic name is compounded of the Ionic form ^vaf; strange, and 

 O-T^JJM, mouth. 



There appear to be many points of resemblance between this genus 

 and Cydodorippe, A. Milne-Edwards, and Clythrocerus of the same 

 author. The figures of Ortmann's Cydodorippe uncifer by Ortmann 

 and Ihle illustrate this, while the differences in the pleou are very 

 marked, as seen in Parisi's illustration of the saine species. 



XEINOSTOMA EUCHEIR, n. sp. 

 Plate XCIX. 



The finely denticulate rostrum is concave above, the surface of the 

 carapace traversed by ill-defined transverse and longitudinal depres- 

 sions, the antero-latero-lateral margins denticulate, a conspicuous 

 tooth at the external corner of the orbit and a similar one near the 

 beginning of the curved setulose postero-lateral border ; the hind 

 margin shallowly excavate. The sternal plastron is acutely produced 

 between the bases of the third maxillipeds in front and deeply excavate 

 behind for the terminal segment of the pleon. In the male the 

 second segment of the pleon is the widest though proximally very 

 narrow ; in the female the third segment is the widest but subequal 

 to the fourth. 



