105 



46. Onesimus Edwardsii, (Kroyer). 



(PL 36, fig. 1.) 

 Anonyx Edwardsii, Kroyer, Nat. Tidsskr. 2 Reekke, Bd. 2, p. 1. 



Body ratlier robust and tumid, with broadly vaulted back. Cephalon 

 about tlie length of the 1st segment of mesosome, lateral corners but slightly 

 projecting and evenly rounded at the tip. First pair of coxal plates rather 

 expanded below; the 2 succeeding ones scarcely twice as deep as the corres- 

 ponding segments; 4th pair somewhat broader, with the posterior expansion 

 short and obtusely truncated; 5th pair nearly as deep as broad. Last pair 

 of epimeral plates of metasome produced at the lateral corners to a narrow 

 slightly upturned lobe. First segment of urosome deeply depressed dorsally. 

 Eyes rather large, oblong oval, slightly expanding below, pigment bright red. 

 Superior antennae in female about the length of the cephalon and the 2 first 

 segments of mesosome combined, 1st joint of the peduncle very large and 

 tumid; fiagellum somewhat longer than the peduncle and composed of about 

 15 articulations, the 1st of which does not exceed the 2 succeeding ones com- 

 bined ; accessory appendage nearly half the length of the fiagellum and 6-ar- 

 ticulate. Inferior antennae a little longer than the superior, flagellum com- 

 posed of about 18 articulations. Anterior gnathopoda with the propodos much 

 longer than the carpus, slightly curved in its outer part, and nearly trans- 

 versely truncated at the tip, palmar edge somewhat arcuate and finely den- 

 ticulated. Posterior gnathopoda very slender, propodos exceeding half the 

 length of the carpus and slightly dilated distally. Posterior pereiopoda rather 

 stout, ineral joint somewhat thickened ; basal joint of last pair oval, equalling 

 in length the remainder part of the leg. Last pair of uropoda with the 

 inner ramus about as long as the basal joint of the outer, and armed on the 

 inner edge with 2 small denticles. Telson rounded, scarcely more long than 

 broad, posterior incision very short, terminal lobes obtusely rounded, each 

 with a very smal denticle. Colour pale reddish yellow ; ova in the marsupial 

 pouch bright orange. Length of adult female 11 mm. 



Remarks. - - The present species may be regarded as the type of the 

 genus. It is easily known from the 2 succeeding species by the obtusely 

 rounded lateral corners of the cephalon, as also by the structure of the an- 

 terior gnathopoda, and partly also by the form of the posterior pereiopoda. 



Occurrence. - -I have myself never met with this form out of the Arc- 

 tic region. According to Boeck, however, it is said to occur rarely at Lyng- 

 holmen in the outer part of the Hardangerfjord, and Bruzelius likewise re- 

 cords the species from the West coast of Norway. In Finmark 1 have found 

 it not unfrequently at depths varying from 20 to 50 fathoms. 



