376 



red. Superior antennae scarcely longer tlum tlie inferior, 1st joint of the 

 peduncle about the length of the other 2 comhined, and, like the 2nd, pro- 

 duced at the end anteriorly to a dentiform projection, flagellum about the 

 length of the pediincle, and densely setous on the anterior edge. Anterior 

 gnathopoda nearly naked, propodos linear and about the length of the 

 carpus, dactylus rather strong, being divided in its oixter part into 7 strongly 

 curved denticles, and having besides the iisual partly-ciliated seta?. Posterior 

 gnathopoda, as usual, somewhat more strongly built than the anterior, and 

 provided in their outer part with fascicles of small setae, propodos about 

 the length of the carpiis, dactylus of normal appearance, and rather curved. 

 Pereiopoda somewhat stronger than in the preceding species, basal joint 

 of the 3 posterior pairs oblong quadrangular in form, and produced at 

 the infero-posteal corner to 2 acuminate projections, of which the outei' is 

 the larger. Last pair of ui'opoda with the inner ramus exceeding the outer 

 by about '/s of its length. Telson rather small, scarcely longer than it is 

 broad, apical incision comparatively deeper than in the preceding species. 

 Colour, according to Boeck, reddish white. Length of adult female 12 mm. 



ItemarJc. — This is the form upon which Owen founded his genus 

 Acanfhonoiits. It is easily distinguishable from the preceding species by the 

 much stronger development of the dorsal carina, and by the very large pro- 

 jections formed by it, as also by the rather ditferent shape of the posterior 

 pairs of coxal plates, and of the last pair of epimeral plates of metasome. 

 Moreover the basal joint of the 3 posterior pairs of pereiopoda exhibit a rather 

 different appearance by the 2 acuminate projections into which the infero- 

 posteal corner is divided. 



Occurrence. — The species seems to be very rare off the coast of 

 Norway, and to be wholly restricted to the arctic region. I have myself only 

 met with it in a single locality off the Lofoten Isles, where 2 specimens were 

 collected, many years ago, from a depth of about 100 fathoms. A single 

 specimen was moreover found by my late fatiier in Ivomagfjord, west Finmark. 



J)is/rihnlioH. — Arctic America (Owen), Spitsbergen (Groes), the Ba- 

 rents Sea (Hoek), the Kara Sea (Hansen). 



Gen. 2. Iphimedia, Rathke, 1843. 



Syn.: Microclieles, Kroyer. 

 ,, Panoplsea, Thomson. 



Body comparatively stout, with the back broadly rounded, and the 

 posterior edge of some of the segments divided into acute lappets. Cephalon 



