OCR Text |
Show 328 DR. H. J. HANSEN ON THE [Nov. 29, Antennulae have the second joint of the peduncle a little shorter than the third and rather slender; fiagellum in the male about as long as the sum of the two proximal joints of the peduncle, six-jointed. Antennae.-Basal joint is distally cut off transversely, its outer angle without any process measuring more than 90°. First thoracic legs very different in the two sexes.-In the adult male they are robust and elongate, a little longer than thorax. Third joint is oblong, gradually expanded above and produced into a rather large, oblong, acute process directed forward ; fourth joint very large, gradually much expanded above and produced into a large plate-shaped process with the end acute ; upper margin and inner side of the expanded part of third and fourth joints with numerous exceedingly long hairs. Fifth joint very large, without dorsal process but strongly expanded below, forming a large subtriangular plate which is slightly produced below in front, with the lower anterior angle rounded and the distal margin nearly as long as the joint; the upper part of the joint is distally vaulted on the exterior side and situated in a much higher plane than the large lower part, which is a thin plate; in this way a* kind of excavation, sharply marked off above, is formed on the outer side of the joint, and the hand can be turned downwards and backwards so that a portion of its inner side becomes overlapped by the thin plate of the fifth joint; the lower margin and inner side of this thin plate are furnished with hairs and setae of very moderate length. The hand is large, not very long but very deep, about ^ as long as deep; from the basal articulation it expands suddenly and strongly downwards so that a free and rather long posterior margin is formed, and the posterior angle is broadly rounded; the upper margin is feebly convex, the lower margin somewhat shorter than the distal end; the palmar edge is very oblique, with two teeth above the middle and a rather small spine at the lower angle which is produced into a triangular tooth ; at the palmar edge and on the lower margin a number of setae of very moderate length. Seventh joint with the claw claw-shaped, rather small and not reaching the lower end of the palmar edge; lower margin of the joint with a row of fine spines.-In the female the first legs are very much smaller than in the male, not elongate. Third and fourth joints as to shape and hairs essentially as in the male, yet somewhat shorter in proportion to length; fifth joint similar to that in the other sex, but the upper angle is produced into a rather short acute process, and the lower plate-like expansion is narrower as compared with the upper portion, Avhich is rather feebly vaulted. The hand is nearly twice as long as deep; the lower margin is rather convex in its proximal half, but a posterior margin, as found in the male, is not developed ; the palmar edge is very oblique, and the angle between this edge and the lower margin measures nearly 130°, the edge shows a rudimentary tooth, several stiff setae pectinate above, and at the lower end a notch so that the usual strong spine |