﻿34: 



PKOCEEDIN&S OF THE 



[June, 1856. 



rated on their edges; rostrum with a line of punctures near the edge, its 

 surface is prolonged backwards, widening as it proceeds, for nearly half the 

 length of the carapax, and is bounded laterally by ridges marked by granu- 

 lations and punctures, from which the general surface of the carapax slopes 

 downwards on each side; these ridges are continued backwards and out- 

 wards with a moderate curvature forwards, and gradually become effaced 

 before reaching the edge of the carapax ; from about the middle of one of 

 these ridges to the other runs a transverse ridge, most distinct at the extre- 

 mities, where it is marked by very prominent tubercles, and at the middle, 

 where it is marked by granulations ; this transverse ridge, which is about 

 midway between the tip of the rostrum and the posterior edge of the cara- 

 pax, is the posterior boundary of a triangular surface, which is the most ele- 

 vated part of the carapax, and from which the surface slopes down on every 

 side ; the anterior portion of this surface, which properly belongs to the ros- 

 trum, is nearly plane, with a slight central depression, the posterior portion 

 separated from the other by a line of granulations, is more undulating and is 

 marked by two slight longitudinal depressions. The form of the carapax 

 maybe compared to that of a frustrum of a low triangular pyramid. 



Exterior antenna, with basal segment small, the second about as broad 

 as long, with a small external tooth ; third segment about equal in length to 

 the first ; Buccal frame a little longer than broad ; third pair of maxillipeds 

 exactly closing the mouth, third segment nearly square, its articulation with 

 the second being near a straight line, and having the fourth segment articu- 

 lated rather on its interior edge than on interior angle. 



Anterior pair of feet sub-equal, about twice as long as carapax : third seg- 

 ment triangularly prismatic, one of the planes forming the upper surface ; the 

 opposite edge (of course beneath) slightly granulated ; posterior edge den- 

 tated, lamellar, and much dilated as it approaches the articulation with the 

 carpus, forming an angle where most dilated ; anterior edge lamellar, and 

 but slightly dilated, dentate, three of the teeth more prominent than the rest, 

 distant ; carpus, with outer edge lamellar, prolonged anteriorly into a tooth ; 

 hand triangularly prismatic, one of the surfaces inferior, the opposite edge 

 superior, crested dentate, teeth large : anterior or outer edge, with three pro- 

 minent distant teeth ; edge of crest between the teeth curved so that the 

 three teeth, with the one on the carpus, enclose three curves, forming fes- 

 toons; superior and exterior edges confluent at articulation of moveable 

 finger ; interior or posterior edge crenate, crenatures marked by pits on both 

 the surfaces which unite to form the edge ; moveable finger falcate, crested, 

 dentate, crest with bifurcations running backwards to condyles of articula- 

 tions ; four posterior pairs of feet, with the third segment armed on anterior 

 and posterior edges with lamellar laciniate teeth; in the second and fifth pair 

 the anterior and posterior sets of teeth are sub-equal, in third and fourth the 

 anterior set are smaller; tarsi styliform, those of second and third pair pro- 



