650 



last 2 pairs much more strongly built, though scarcely as long as the ante- 

 penultimate pair, propodal joint very strong and somewhat curved, fully twice 

 as long as the carpal one, with the palmar edge spinulose and defined by a 

 distinct triangular projection, dactylus strong, falciform. Urosome very small, 

 provided on each side with a number of stiff bristles, but without any true 

 appendages. Body whitish, pellucid, more or less variegated with a reddish 

 brown pigment, forming generally on each side of the marsupial pouch 2 

 large stellate patches. Length of adult female 12 mm. 



Remarks. - - This form was first described by Montagu as Cancer 

 pliasma, and has been subsequently recorded by different authors under seve- 

 ral other names mentioned above as synonyms. The JEyina Icevis of Boeck is 

 apparently only based on immature specimens of the present form, in which 

 the dorsal spines have not yet developed. In the adult state it may be 

 easily recognized from the other northern Caprellidse by the peculiar arma- 

 ture of the anterior part of the body, the extremely elongated superior an- 

 tennae, and the structure of the posterior gnathopoda. The rudiments of the 

 2 anterior pairs of pereiopoda will suffice to distinguish it from the species 

 of the genus JEgina. to which it otherwise bears a close resemblance. 



Occurrence. I have only met with this form in a few localities of 

 the south coast of Norway (Risor, Arendal), clinging to Hydroida in depths 

 ranging from 20 40 fath. According to Boeck, it also occurs off the west 

 coast of Norway (Karmo), as also in the Christianiafjord. 



Distribution. British Isles (Sp. Bate), Kattegat (Meinert), coast of 

 France (Chevreux), Mediterranean (P. Mayer), Adriatic (Heller), Azores (Barrois). 



Gen. 3. JEgina, Kreyer, 1843. 



Body of a similar slender form to that in the preceding genus, sometimes 

 smooth, sometimes coarsely spinous. Antennae about as in that genus. Oral 

 parts differing in the fact of the mandibular palps being somewhat less elongated, 

 and the masticatory lobes of the maxillipeds strongly spinous inside. Griiatho- 

 jioda resembling in structure those in the genus Protdla. The 2 anterior 

 pairs of pereiopoda wholly absent, not even the slightest rudiment being 

 observable; the 3 posterior pairs strongly developed, and of equal structure, 

 with the propodal joint large and expanded at the base. Branchial lamellae 

 only present on the 3rd and 4th segments of mesosome. Urosome in both 

 ixes with : \ pairs of appendages, the anterior ones biarticulate, the posterior, 

 uniartioulate. 



