53 



triangular (fig. 2 //), but the outer angle is distinctly, the inner very broadly, rounded. Exopod 

 of third pair (fig. 2 /i) not fully twice as long as the endopod ; counting its joints from the 

 distal end the two first joints are short, simple, but the 3 distal seta; of the terminal joint 

 and the outer setse of the other joint are proportionately short ; the six following joints 

 — counted from the distal end — each at the outer side with a protuberance increasing 

 in size and especially in breadth from the most proximal to the most distal of these joints 

 (fig. 2/); counting again from the distal end of the ramus fifth, sixth, seventh and eighth — 

 in small specimens only fifth, sixth and sometimes seventh — joints each on the outer .side 

 with a slender process directed outwards and somewhat forwards and terminating in a fine, 

 naked seta. 



Uropods (fig. 2 k) with the endopod somewhat broad and at least reaching the end of 

 telson; exopod considerably shorter than the endopod, with the end angular and the outer 

 margin furnished from the end to rather near the base with a large number of spines, nearly 

 all short, only the three or four most distal increasing gradually somewhat in length. Telson 

 about two and a half times as long as broad (fig. 2 k), tapering gradually and very moderately 

 in breadth from the base to near the end; the lateral margins along about two-thirds of their 

 length with numerous spines somewhat unequal in length, and several among them moderately 

 long; the terminal incision so narrow at the bottom that the spines from the opposite sides 

 nearly reach each other; the terminal pair of spines long. 



Length of the male 6 mm., of the female 4.5 mm.; the Kroyerian male type preserved 

 in the Copenhagen Museum measures 7.0 mm. in length. 



Remarks. — A. truncata G. O. Sars = A. typica G. O. Sars (not Kroyer) differs 

 from the real A. t\pica Kr. in a number of features. The frontal plate is a little longer with 

 the transverse, straight terminal margin; the eye-stalks seem to be shorter; the protruding part 

 of the fifth joint of the male gnathopods is more removed from the distal end of the joint ; 

 the sixth joint of the first pair of the thoracic legs in the male is quite different, being divided 

 into 3 subjoints with about i i long, cylindrical seta; distributed along the distal two-fifths of 

 the interior margin of the joint and on its end; the pseudobranchial plate of the male pleopods 

 has the outer angle sharp and setose; finally the exopod of third pleopods (not fourth pair, 

 as stated by Sars) is extremely different, resembling much more a normal ramus. 



Distribution. — Kroyer's two specimens of A. typica were taken in the tropical 

 Atlantic, lat. 14° N. The Copenhagen Museum possesses a good number of .specimens of this 

 species taken in Cruz Bay, St. Jan, Danish West-Indies, together with a large number of other 

 Plankton-Crustacea by Mag. sc. C. Lofting (Jan. 10, 1896). F"urthermore it was taken by Dr. 

 Th. Mortensen North of St. Thomas, West-Indies (i specimen) and at two localities in the 

 Gulf of Siam, viz. near Koh-si-Chang, 10 — 15 fathoms (i specimen) and in the Bay of Rayong, 

 7 — 10 fathoms (i specimen). — Statements in the literature on the capture of A. typica ought 

 tc be regarded with doubt until the specimens mentioned have been re-examined; it may, 

 however, be added that the specimens mentioned by Ortmann in his paper "Schizopods of the 

 Hawaiian Islands" (Bull. U. S. Comm. Fish and Fisheries for 1903, p. 972 — 973), according 

 to his remarks on first pair of legs in the male, certainly belong to A. typica Kr. 



