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small, scarcely exceeding in length the last peduncular joint. Anterior gna- 

 thopoda with the basal joint rather thick in its proximal part, outer part of 

 the leg extremely slender, and nearly naked, carpus narrow and elongated, 

 propodos much shorter, and somewhat curved, with the chela extremely small, 

 though normally developed. Posterior gnathopoda rather strongly built, carpus 

 comparatively short and, like the meral joint, produced at the end inferiorly 

 to a narrow lobe, propodos very large and broad, triangular in form, with 

 the palm nearly transverse, and finely denticulated. Pereiopoda rather short 

 and stout, with the meral joint produced at the end to a narrow acuminate 

 projection reaching, on the posterior pairs, beyond the carpal joint, dactylus 

 in all strong and curved, basal joint of the 3 posterior pairs quadrangular 

 in form, infero-posteal corner broadly emarginated at the tip, or slightly 

 bilobate. Last pair of uropoda with the outer ramus scarcely more than 

 half as long as the inner, and also much narrower. Telson rather prolonged, 

 more than twice as long as it is broad, outer part tapering, tip minutely 

 incised. Colour rather variable, now whitish, now variegated with irregular 

 dark brown shadows, which sometimes occupy the whole anterior part of 

 the body. Length of adult female scarcely exceeding 5 mm. 



Remarks. This is a very distinct and easily recognizable form, 

 differing, as it does, rather markedly from the other Ipliimididce, both as 

 to external appearance and in some of the structural details, though evi- 

 dently belonging to that family, as first pointed out by Boeck. The latter 

 author has however fallen into a strange error as regards the gnathopoda, 

 which have been confounded in such a manner, that the posterior ones are 

 described as the anterior, and vice versa. 



Occurrence. Though nowhere in any abundance, I have met with 

 this form in several places, both off the Finmark coast, and off the west 

 and south coasts of Norway as far as the Christianiafjord. It is generally 

 found in moderate depths, on rocky bottom, among algse and Hydroida, but 

 always quite solitary. 



Distribution. Shetland Isles (Sp. Bate), Arctic America (Torell), 

 Greenland (Hansen), Spitsbergen (Goes). 



Fam. 14. Laphystiidae. 



Body more or less depressed, with thin and flexible integuments. 

 Cephalon produced in front to a Hattened horizontally projected rostral 



