228 CRUSTACEA. 



incurved at apex, and when shut the tips alone close together. The 

 spines of the inner margin nearest the apex are the smaller. On 

 the outer side, towards the extremity, the fingers bear recurved hairs. 

 The female abdomen is very broad oval, and consists of seven seg- 

 ments. The inter-orbital space is scarcely one-third the breadth of 

 the carapax. The inner antennae occupy transverse fossettes situated 

 mostly anterior to a line between the orbits. 



FAMILY III. ERIPHID^. 



THE ridge upon the proalabial area or palate is prominent in Eriphia 

 and Ruppellia, and a deep rounded emargination in the margin of the 

 buccal area marks the termination of the efferent canal. A similar 

 emargination, less distinct, exists in some other genera, as Trapezia and 

 Ozius. Traces of this ridge are seen in some of the Cancridae, as in 

 certain Actaeae, Paraxanthi, Pseudocarcini, &c. ; but in these species, 

 it is quite small, and stops far short of the anterior margin of the 

 buccal area. In Pilumnoides it is very distinct and prominent, and it 

 is also apparent in the Pilumni, although these species have in many 

 respects the habit and form of some Xanthodes, in which the ridge is 

 wanting or is obsolescent. In a few Pilumni it stops a little short of 

 the anterior margin ; but it is continued anterior to the first episternal 

 suture which crosses the surface, which suture is indicated by a notch 

 in the ridge, and is shown in our figure of the praelabial area of Pseu- 

 dozius planus, pi. 13, fig. 6 ; the ridge has often a slight interruption 

 at this point. 



This family may be divided into subfamilies, on the same grounds 

 nearly as the Cancridae. The subfamily Cancrinae is represented in 

 this group by (Ethrinse, and a general parallelism is easily made out 

 between the other subfamilies. These subdivisions and the genera 

 included, with their characteristics, are presented in the following 

 table : 



1. CETHRIN^E. Carapax transversus, lateribus valde dilatatus et 

 rotundatus. Antennas internee fere longitudinales. 

 G. 1. CEiHRA, Leach. 



