143 



the superior ones provided with a well-developed accessory appendag;e; those 

 in male more or less modified. Ejiistome not projecting. Anterior and post- 

 erior lips aljout as in the Fontoporciidce. Mandibles very short, masticatory 

 ]iart but little expanded and strongly incurved, cutting edge well-developed, 

 molar expansion generally very slight, palp rather large. Maxillae extremely 

 small, 1st ])air with the palp poorly developed, basal lobe small and .simple; 

 2nd pair with both lobes short and rounded at the ti]i. Maxillipeds with the 

 masticatory and basal lobes poorly developed, palp on the other hand large 

 and pediform. Gnathopoda subsimilar, rather powerful, witli large distinctly 

 subcheliform hands, the palmar edge of which is defined posteriorly by a more 

 or less projecting thumb-like process armed inside with a strong spine. An- 

 terior pereiopoda of the usual structure, the 3 posterior pairs rather dissimilar, 

 penultimate pair hy far the longest, last pair with the basal joint laminarly 

 expanded. Branchial lamellae simple. Pleopoda in female rather small, in 

 male much more powerful. The 2 anterior pairs of uropoda normal; last 

 pair, as a rule, rather small, with the outer ramus biarticulate and spinous 

 in female. Telson small, cleft to the base. 



Remarlcs. — This family is nearly allied to the Pontoporeiidoi, with 

 which I have formerly combined it. As it however contains several closely 

 allied genera, I prefer, at present, to keep it apart as a separate family. 

 Tlie most striking feature of the forms comprised in this family, is undoubtedly 

 the peculiar form of the cephalon, which is produced in front in tlie form of 

 a hood, covering over the bases of the antennee. The powerful structure of the 

 gnathopoda also affords a well-marked characteristic to distinguish them from 

 the Pontoporeiidse. As to habits, all the forms are true burrowers, consequently 

 occurring only where the bottom consists of loose material, as sand or mud. 

 The family comprises, as yet, 4 genera, all of which are represented in the 

 fauna of Norway. 



Gen. \. PhoXOCephaluS, Stebbing, 1888. 

 Syu : Pliuxiis, Kroyer (part). 



Body rather stout and moderately compressed. Hood of the cephalon 

 acute. The 4 anterior pairs of coxal plates successively increasing in size 

 posteriorly and provided inferiorly with a few simple bristles; 4th pair not 

 very much expanded distally and but slightly emarginated posteriori^' in their 

 upper part; 5th pair with the posterior lobe rounded. Superior antennae 

 shorter than the inferior; the latter in male very elongated and slender, with the 

 tiagellum filiform and ]n'ovided with distinct calceolae. Mandibles rather stout. 



