DECAPODA. 191 



much smaller than the preceding ones. The under part of the tail is 

 never furnished with more than four pair of appendages or false 

 feet *. The lateral fins of the end of the tail, or the pieces which 

 represent them, are thrown on the side and do not form with the 

 last segment a flabelliform fin. 



The ocular pedicles are generally longer than those of the Ma- 

 croura belonging to the following sections. 



Here (the Hippides, Latr.), all the superior teguments are solid. 

 The two anterior feet sometimes terminated in a monodactyle hand, 

 or one without a finger, in the manner of a palette, and sometimes 

 in a point; the six or four following ones end in a fin ; the two last 

 are filiform, reflexed, and situated at the inferior origin of the tail. 

 The latter becomes suddenly narrowed immediately after the first 

 segment, which is short and broad ; the last is in the form of an 

 elongated triangle, and the lateral appendages of the penultimate in 

 that of curved fins. There are four pairs of sub-caudal appendages, 

 composed of a very slender and filiform stem. The antennae are very 

 pilose or strongly ciliated ; the lateral first incline to the intermediate, 

 and are then arcuated or contorted outwards. 



Albunea, Fabr. 

 The two anterior feet, terminated by a very compressed triangular, 

 monodactyle hand ; the last joint of the following ones falciform. 

 The lateral antennae arc short, and the intermediate ones are termi- 

 nated by a single long and setaceous filament. The ocular pedicles 

 occupy the middle of the front, and form, together, a sort of flat trian- 

 gular snout, with the external sides arcuated. The shell is almost 

 plane, and nearly square ; the posterior angles are rounded, and their 

 anterior margin finely dentated. 



The only well known species, Cancer symnista, L, ; Albunea 

 symnista, Fabr,. Herbst., XXII, 2 ; Desmar., Consider., xxix., 3, 

 inhabits the Indian Ocean f , 

 If the Cancer carabus of Linnaeus belong to the same subgenus, a 

 species would be found in the Mediterranean. 



HippA, Fab. — Emerita, Gronov. 

 The two anterior feet terminated by a strongly compressed, 

 nearly ovoid and adactyle hand : the lateral antennae much shorter 

 than the intermediate, and contorted ; the latter terminated by two 

 short, obtuse filaments placed one on the other ; the ocular pedicles 

 long and filiform, and the third joint of the foot-jaws very large and 



* With the exception of the two that are anterior, these appendages in the males 

 are mere rudiments, or are even wanting:, a character common'to the Galatheae 

 Scyllari, and Palinuri. We should also observe that in these three subgenera the 

 caudal fins are thinner or almost membranous at their posterior extremity. In this 

 section, as well as in the Galatheje, the thoracic portion to which the two posterior 

 feet are attached forms a sort of petiole, so that these feet seem to be annexed to 

 the tail. 



t M. Desmarest hesitatingly places the genus Posydon of Fabricius, who speaks 

 of two species, near the Albuneae ; but according to the latter the anterior antennae 

 are bifid, a character which does not belong to the Albuneae. Owing to the imper- 

 fect manner in which he describes this genus, we are not able to recognize it, or to 

 appreciate its affinities. 



