2 Mr. C. S. Bate on the Morphology of some Amphipoda 



for the British Museum (which is near its completion) have en- 

 abled me to make some observations that certainly in one direc- 

 tion must extend our knowledge of these creatures. In the 

 collection of unexamined Amphipoda that was kindly entrusted 

 to me by M. Milne-Edwards, belonging to the Museum of the 

 Jardin des Plantes, were specimens of three species, each bear- 

 ing young animals within the incubatory pouch. These species 

 fortunately belong to three separate genera, namely : Vibilia, 

 Edwards ; Platyscelus and Brachyscelus, mihi. 



Vibilia has been described by Milne-Edwards ; and there will 

 be no occasion to do more than allude to those organs that ex- 

 hibit a difference of form in the adult and the larva. The 

 species is a new one, and may be recognized by the specific name 

 of V. Edwardsii. 



The superior antennae consist of a peduncle formed of one 

 long and two very short joints, and a flagellum formed of one 

 short, broad, obtuse-pointed, compressed articulus. The inferior 

 antennae are short, and consist of two long joints and several 

 short articuli. The gnathopoda are imperfectly complexly sub- 

 chelate. The first two pairs of pereiopoda are simple, and a little 

 longer than the gnathopoda ; the third and fourth pairs are twice 

 the length of the preceding, and have the propodos nearly as 

 long as all the other joints, with the anterior margin ser- 

 rated ; the fifth pair are shorter and more feeble in appearance 

 than the third. The three anterior pairs of pleopoda are normal 

 in form : the three posterior are flat, broad, biramous ; rami 

 lanceolate. Telson narrow and triangular. 

 Length ^ inch. Larva -^ of an inch. 

 Hah. " Near lies de Powel. Eocpedit. de la Zelee" {Label on 

 bottle) . 



The larva of Vibilia Edwardsii has the peduncle of the supe- 

 rior antennae consisting of three joints gradually decreasing in 

 size, and a flagellum consisting of four articuli gradually de- 

 creasing in size, the two terminal being tipped with short hairs. 

 The inferior antennae consist of a single joint, cylindrical, short, 

 and subapically tipped with two curved hairs. The gnathopoda 

 are uniform, short, consisting of five subequally short joints and 

 a narrow and obtuse terminal one. The first two pairs of pereio- 

 poda are longer than the gnathopoda, and are simple in form. 

 The third pair are not much longer than the second, and have 

 the carpus antero-distally produced into a long process ; the pro- 

 podos distally increases in diameter, and is latero-distally pro- 

 duced on each side of the articulation with the dactylos to a 

 sharp point, the anterior surface being concave; the dactylos, when 

 closed, impinges against the hollow of the propodos. The fourth 

 pair resembles the third, except that the antero-distal angle of the 



