DECAPODA. 29 



Hepatus, Latr. 



The Hepati have a considerable affinity with the true Crabs in the 

 widened form of their shell, and the shortness of their lateral anten- 

 nae, approaching the Mursiae and Calappas in their compressed 

 hands, the upper edge of which resembles a crest; but the third joint 

 of their external foot-jaws forms an elongated, narrow, and pointed 

 triangle, without any apparent emargination, a character also ob- 

 served in the Matutas and Leucosias. 



The species(l) which served as the type of this division was 

 confounded by Fabricius with the Calapp. It is as large as an 

 ordinary Pagarus. The shell is yellowish, dotted with red, and 

 the margins finely and unequally crenulated. The eyes are 

 small and approximated, and the feet are traversed by red 

 bands. Although the tail of the male has but five complete seg- 

 ments, the traces of two others may still be discovered on the 

 sides. This species is common at the Antilles. 

 In our third section or that of the Quadrilatera, the shell is 

 nearly square or heart-shaped, the front generally prolonged, in- 

 flected or much inclined, and forming a sort of clypeus. There 

 are seven segments, distinctly marked across their whole breadth, 

 in the tail of both sexes. The antennas are usually very short. 

 The eyes of most of them are fixed on long or stout pedicles. 

 Several live habitually on land, inhabiting holes excavated by them- 

 selves; others frequent fresh water streams. They move with great 

 swiftness(2). 



A first division will comprise those in which the fourth joint of 

 the external foot-jaws is inserted at the superior internal extremity 

 of the preceding one, either in a short, truncated projection, or in a 

 sinus of the inner margin. They approach nearest to the Crabs 

 proper. 



The shell of some is nearly square, or a trapezium, but not trans- 

 verse, or almost in the form of a truncated heart. The ocular pedi- 

 cles are short, and inserted either near the lateral and anterior an- 

 gles of the shell, or more internally, but always at a considerable 

 distance from the middle of the front. Here comes the 



(1) Hepatus fasciatus, Latr. ; Desmar., Consider., IX, 2; Calappa angustata, 

 Fabr. ; Cancer princeps, Bosc; Herbst., xxxvii, 2. See also his Cancer armadillus, 

 VI, 42, 43. 



(2) I consider them, with respect to their habits and some of the characters 

 of their organization, as being- the furthest removed from the other Decapoda; 

 they should be placed at one of the extremities of that order- 



