221 

 4. Amphilochoides odontonyx, (Boeck). 



(PI. 75, fig. 2). 

 AmpMlocUus odontonyx, Boeck, Crust, amph. bor. & arct. p. 51. 



Body somewhat slender, as compared with the other Amphilochidse, 

 and not very compressed, with the back broadly rounded. Integuments rather 

 firm, and exhibiting a peculiar squamous sculpturing. Cephalon about the 

 length of the first 2 segments of mesosome combined, not very deep, somewhat 

 flattened above, rostrum rather large and strongly curved, reaching about 

 to the end of the basal joint of the superior antennae, lateral corners but 

 little projecting, and nearly rectangular. First pair of coxal plates rather 

 small, obliquely quadrangular, anterior corner tapering to an acute point; 

 2nd pair somewhat expanded in their outer part, distal edge transversely 

 truncated, and slightly denticulated in its posterior part, 4th pair not quite 

 twice as deep as the corresponding segment, but rather broad; 5th pair com- 

 paratively small. Last pair of epimeral plates of metasome produced at the 

 lateral corners to a tooth-like projection, defined above by a distinct sinus, 

 posterior edge strongly curved in its lower part. Eyes rather large, rounded 

 oval, with well-developed visual elements, pigment dark red. Superior an- 

 tenna? about the length of the cephalon and the 1st segment of mesosome 

 combined, joints of the peduncle successively decreasing in size, 2nd joint 

 produced at the end inside to an acuminate lappet, flagellum but little 

 exceeding half the length of the peduncle, and composed of about 7 articu- 

 lations. Inferior antennae somewhat longer than the superior, last joint of 

 the peduncle much shorter than the penultimate one, flagellum 7-articulate, 

 and scarcely exceeding half the length of the peduncle. Anterior gnathopoda 

 with the propodos about the length of the basal joint, oblong triangular, 

 fully twice as long as it is broad, palm very oblique, and finely denticulated. 

 Posterior gnathopoda much stronger, propodos exceeding the length of the 

 basal joint, and nearly subfusiform in shape, palm much longer than the hind 

 margin, and scarcely defined posteriorly by any distinct angle, its edge 

 slightly curved, and finely denticulated throughout, carpal process somewhat 

 dilated in the middle, and reaching about to the palm, dactylus in both pairs 

 strongly curved at the base, and provided inside with a well-marked nodiform 

 denticle, its outer part smooth and ver}' slender. Basal joint of the 3 pos- 

 terior pairs of pereiopoda very broad, especially that of the last pair, pos- 

 terior edge finely serrulate. Last pair of uropoda of moderate size, scarcely 

 reaching beyond the 1st pair, basal part somewhat longer than the rami. 

 Telson rather large, projecting beyond the basal part of the last pair of 

 uropoda, and gradually tapering from the base to the tip, which on the left 

 side has a small secondary denticle. Body yellowish, mottled with reddish 



28 Crustacea. 



