142 AMPniPODA NORM ALIA. 



as long as broftclth of joint, those of the upper margin shorter. 

 Three posterior pairs of pleopoda witli numerous spinulcs; the 

 branches of the antepenultimate pair styliform, those of the last 

 pair rather long and narrow, foliaccous, acuminate ; margins 

 edged with many spinules. 

 " Length 4 lines. 



♦' Ilah. Capo of Good Hope." — Dana. 



15. Atylus vulgaris. 



Iphimedia vulgaris, Stimpson, Marine Invert, of Grand Manan, p. 53. 



" Smooth, subcompressed. Pleon with segments slightly projecting 

 at the articulations, but not dcntated. Head large, with veiy 

 largo reniforra eyes, which are colourless in preserved specimens. 

 Antennae subequal, with very long, slender, filiform flagella; and 

 in length about equalling that of the body ; the superior ones 

 thick-based, and a little the larger. Mandibles with sharp curved 

 apices, and large appendages consisting of three joints, the basal 

 one of which is very short, the second broad, and the terminal one 

 very slender. Maxilhpeds slender, pointed, with large internal 

 lamellte. Gnathopoda small, those of the first pair the larger. 

 Pereiopoda very slender, terminating in curved dactyla. Three 

 anterior pairs of pleopoda well developed; the two penultimate 

 pairs almost acicular, with small spines above ; posterior pair with 

 broad lancet-shaped rami. Telson tenninating in two lamelli- 

 form spines. Coloiu' variable, generally dark-mottled purplish. 



" Length of a large specimen about 0'4 inch. 



" Ilab. In little pools loft by the tide among the rocks near low- 

 water mark. They are very active, swimming about in all direc- 

 tions, and seldom resting long in one place." — Stlmj^son. 



Stimpson says that this species differs but slightly from A. inermis, 

 Kroyer. He also describes the "tail" as "terminating in two 

 lamelliform spines ; " but it is not sufliciently clear from this whether 

 the telson is only di\4ded or double. 



16. Atylus compressus. 



Amphitoe compressa, Liljehorg, Of vers, af Konyh Vetensk. Akad. For- 

 Juindl. p. 8, 1852. 



" Body considerably compressed ; dorsal Kne throughout its whole 



length carinated. Coxa; large. Cephalon with a compressed, 



acute, deflexed rostrum. Fourth, fifth and sixth segments of the 



pleon each furnished with a single tooth on the median dorsal line, 



that on the fifth being the greatest, and that on the sixth the 



smallest. Eyes large, rcniform, black. Inferior pair of antennae 



