AMP¥1P0DA. 89 



two of the antennas, at least half as long as the body and terminated 

 by a long setaceous stem composed of several small joints(l). 



Phrosine, Risso. 



Form of the body and that of the head similar to the Hyperiae, but 

 the antennae, at most, the length of the latter, composed of but few 

 and styliform joints, or terminated by a stem resembling an elon- 

 gated cone(2j. 



Dactylocera, Lat, 



The body not thickened anterior'lyj the head moderate, depressed, 

 nearly squarej eyes small ; four extremely short antennae composed 

 of but few joints, as in Phrosine, of various forms — the inferior 

 being thin and styliform,. and the superior terminated by a small 

 concave plate on the inner side — i-esemble a spoon or forceps(3). 



The others — Gammarin^, Latr. — always have four antennae j their 

 body, invested with coriaceous and elastic tegments, is generally 

 compressed and arcuated ; the posterior extremity of the tail is de- 

 prived of fins J its appendages are styliform and cylindrical, or coni- 



(1) Cancer monoculoides, Montag'., Trans. Lin. Soc. XI, ii, .3; — Hyp^rie de Le- 

 sueur, Lat, Encyclop. Mahod., Atl. d'Hist. Nat., CCCXXVIII, 17, 18; Desmar. 

 Consid., p. 258. 



N.B. Near the Hyperix should be placed the genus Themisto, Lat., carefully 

 figured and described in the Mem. de la Soc. d'Hist. Nat., tome IV. As in the 

 Hyperiae, the eyes are very large and occupy the larger portion of the head; two 

 of the antennae (the inferigr), all terminated by a multi-articulated stem tapering to 

 a point, are evidently longer than the others. The part there called levre inferieure, 

 is the ligula; those which appeared to form the third pair of jaws are the first 

 of the foot-jaws, and, as in the Amphipoda and Isopoda, close the mouth inferiorly 

 under the form of a lip. The four remaining foot-jaws ai-e very short, directed 

 forwards and laid upon the mouth in such a way that they seem to constitute a 

 part of it, so that if we do not count them, or if we merely consider the following 

 locomotive and much more apparent organs as feet, this animal, like the Hyperia 

 and Phrosine, appears at the first glance to have but ten feet instead of fourteen. 

 The third pair of foot-jaws is terminated by a small didactyle forceps. The same 

 pair of feet, properly so called, is much longer than the others; its penultimate 

 joint is greatly elongated, and is armed with a range of small spines forming a sort 

 of comb. But a single species is known. 



(2) Phros. macrophthalma, Risso, Journ. de Phys., Octob, 1822; Desmar., lb., p. 

 259; Cancer galba, Montag., Trans., Lin. Soc, XI, ii, 2. 



(3) Fhros. seminulata, Ilisso, lb.; Desmar., lb. The stem of the inferior antennae 

 consists of two or thi-ee joints, while in Phrosine it is inarticulate. There also, 

 the joints of the peduncles of the same antennae are shorter. 



Vol. Ill— M 



