60 Notes 071 North American Crustacea. 



this interesting Crustacean. Our specimens, however, were 

 found at Panama, by Mr. Sternbergh, so that its geographical 

 range must be on the tropical parts of the western shores of 

 America. 



An examination of the alcoholic specimens, in the Smith- 

 sonian Museum, enables us to determine that in this genus the 

 male verges arise from the coxa3 of the posterior pair of feet, 

 and are lodged and concealed in the chinks separating the ster- 

 nal pieces of the sixth and seventh thoracic segments. There 

 is no ridge upon the palate or endostome. 



Eiiryplax, nov. gen. 



Carapax transverse, broad ; antero-lateral margin very short, dentated ; 

 facial region of less width than the carapax ; front nearly half as broad 

 as the carapax ; ocular peduncles of moderate length ; external antennae 

 excluded from the orbit by the internal suborbital lobe, which joins the 

 front. External maxillipeds with the palpus of the endognath articu- 

 lated to the short meros at its truncated, inner angle, as in the Can- 

 croids. Palate with a distinct ridge on each side, defining the efferent 

 channel. Chelipeds large and thick ; a circular pit on the front side 

 of the meros-joint near its extremity. Ambulatory feet compressed ; 

 dactyli of posterior pair short and compressed. Verges of the male 

 arising from the coxa3 of the posterior feet, and passing to the abdomi- 

 nal appendages through canals in the sternum. Basal joints of the 

 abdomen almost entirely covering the seventh joint of the sternum, a 

 portion of which, however, is exposed to view on each side at the late- 

 ral sinuses of the abdomen, which occur between its second and third 

 joints. None of the abdominal segments are soldered together. 



This genus differs from Prionojplax^ PseudorJiombilq, etc., 

 in the characters of the orbits. 



Eiaa'ygslas. MifidBas, nov. sp. 



Carapax smooth and shining, convex in a longitudinal sense. Pro- 



