KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 11 



The head is not produced, shorter than the first three pereional segments. The first pair of 

 antenna with the fiagellum suddenly narrowed, the terminal part cylindrical. The first 

 pereional segment is the shortest, the fourth, fifth and sixth the longest. The first four 

 pairs of epimerals are not deeper than the following. The carpus of the first pair of 

 pereiopoda is broad, not produced, longer than the metacarpus; the metacarpus is com- 

 plexly serrated. The carpus of the second pair is produced, strongly serrated, longer 

 than the metacarpus. The metacarpi of the fifth and sixth pairs are much longer than 

 the carpi. The seventh pair are longer than the femur of the sixth pair; the femur of 

 the seventh pair is twice longer than all the following joints together; the posterior margin 

 is straight, not excavated. The lateral parts of the first two phonal segments are rounded, 

 posteriorly serrated, those of the last segment feebly rounded, not serrated. The second 

 and third ural segments are free, not coalesced. The peduncles of the first and second 

 pairs of uropoda are a little shorter than the rami; the peduncle of the last pair is 

 twice as long as the rami. The telson is semicircular, much shorter than the last ural 

 segment, equalling a fourth of the length of the peduncle of the last pair of uropoda. 



Colour. Bluish green. 



Length. 15—22 mm. 



Hab. The South Atlantic, at various localities between Lat. 30° — 60° S. Indian Ocean, the South 

 Pacific. 



Syil. 1887. Cyllopus armatus, C. BOVALLIUS. "Systematical list of the Amphipoda Hyperiidea». Bih. 



t. K. Sv. Vet. Ak. Handl. Bd. 11. N:o 16, p. 11. 

 » » » 1887. »Arctic and Antarctic Hyperidsw. Vega-Exp. Vetensk. 



lakttagelser. Bd. II, p. 557. PI. 41, fig. 15—25. 



As I have not been able to identify this species, the most common of all, with any 

 of the previously described ones, I have been compelled to propose for it a new specific 

 name. It is not impossible, however, that a closer examination of the typical specimen 

 of Spence Bate's Cyllopus magellanicus (— Cyllopus Batei, mihi,) will prove the both species 

 to be identical. All the species of this genus seem to be closely connected with each other 

 so that it is very difficult to point out good specific characteristics, but Cyllopus arma- 

 tus may be recognized easily enough by the complexly serrated metacarpus of the first 

 pair of pereiopoda, the strong but irregular serration of the same joint of the second pair, 

 the equal depth of all the epimerals and by the length of the last ural segment. The 

 sexual difference is marked in the breadth of the pereion of the female, and in its length 

 in comparison with the pleon, and also in the form of the first pair of antennas. The 

 form of the second pair of antennas is, contrary to most of the other Hyperids, almost 

 the same in both sexes. 



The body of the female is higher and broader, in comparison with the legs, than 

 the body of the male. 



The head is almost globular, as long as the first two pereional segments and half 

 the third. 



The eyes occupy the whole surface of the head except a narrow, longitudinal stripe 

 on the summit of the head. 



