464 



the peduncle neavh- twice as long as the penultimate one, flagellum about 

 the length of those joints comLined. I>otli pairs of antennae in male much 

 more elongated than in female, and having the opposite edges of .the peduncles 

 densely clothed with fascicles of delicate sensorj' bristles. Anterior gnatho- 

 poda comparatively rather strongly built, propodos regularly ovate in form, 

 and about the length of the 3 preceding joints combined, its upper face 

 densely clothed with transverse rows of slender bristles, palm very oblique, 

 and imperfectly defined posteriorly. Posterior gnathopoda somewhat more 

 slender than the antei'ior, with the propodos narrower and scarcely longer 

 than the 2 preceding joints combined, palm shorter than the hind margin, 

 and defined below by on obtuse angle. Pereiopoda rather short; the 2 

 anterior pairs of the usual structure; the 3 posterior pairs having the 

 propodal joint much longer than the carpal one, and the dactylus recurved, 

 basal joint of the antepenultimate pair with the anterior edge strongly curved, 

 and densely clothed with long cilia, infero-posteal corner produced to a 

 triangularly pointed projection, that of last pair broadly oval in form, and 

 having likewise the infero-posteal corner produced to a triangular deflexed 

 lappet. Branchial lamellae of the 3 anterior pairs of pereiopoda distinctly 

 lobular. Last pair of uropoda with the rami more than twice as long as the 

 basal part, each with a well-marked apical spine and a few simjjle bristles. 

 Telson not nearly twice as long as it is broad at the base, cleft very narrow, 

 and extending nearly to the base, terminal lobes truncated at the tip, and 

 each carrying a single small apical spinule. Body semipelliicid, whitish, with 

 small scattered patches of a chestnut-brown pigment. Length of adult female 

 8 mm., of male somewhat less. 



Eeinails. — The present form was first described in the year 1830 

 by M-Edwards as AmpJn'thoe Sivammerdami, and was subsequentlj- referred by 

 Sp. Bate to the genus Ahjlus of Leach. According to the latter author, the 

 forms, he had previously described as Dexamine Gonloniana and D. Loughrini, 

 are not speeitically different from that species, and the same is also undoubt- 

 eA\y the case with Antpliithoc compressa of Lilljeborg. From most of the 

 other species, the present one may Ije easily distinguished by its comparatively 

 short and stout body, and the want of any dorsal projections, except those 

 of the 1st segment of urosome. 



Orcurrence. — I have met with this form rather abundantly in several 

 places, both off the south and west coasts of Norway, as also off the whole 

 Finmark coast as far as Vadse. It it generalh- found in comparatively 

 shallow water, from 3 to 20 fathoms, and especially where the bottom 

 consists of pure sand. As usual, the males are much more active than the 

 females, and swim about with great rapidity. 



