_661_ 



denticulated spines. Body, according to Boeck, of a light colour, mottled 

 with dark specks. Length of adult female 15 mm. 



Remarks. The present species, established by Boeck, is nearly allied 

 to C. septentrionalis, and is considered by Dr. P. Mayer to be only a variety 

 of this form. I have never, however, among the numerous arctic specimens 

 examined of the above-named species, found any attempt to the peculiar 

 spinous armature distinguishing the present species, and as there are also some 

 differences in the structure of the several appendages, I have felt justified in 

 maintaining this form as a distinct species. Prof. Meinert would also seem 

 to have some doubt about the identification made by Dr. Mayer. According 

 to Boeck, the male does not differ much from the female; but it is most 

 probable, that he has only examined young, not yet sexually developed males. 



Occurrence. - I have met with this species occasionally off the west 

 coast of Norway, in comparatively shallow water among algae. Boeck records 

 it from Sondmore and from the Trondhjemsfjord. 



Distribution. Kattegat (Meinert). 



9. Caprella monocera, Gr. 0. Sars, n. sp. 



(PI. 238, fig. 1). 



extremely slender and elongated, especially in the male, with 

 scattered small tubercles dorsally. Cephalosome with a single, erect, corni- 

 form tubercle (not bifurcate) in front of the cervical impression. Each of 

 the 3 succeeding segments witli a single dorsal tubercle about in the middle; 

 antepenultimate segment scarcely longer than the preceding ones, and having 

 3 pairs of small dorsal tubercles. Eyes very small, orbicular. Superior 

 antennae comparatively slender and elongated, exceeding half the length of 

 the body, 2nd joint of the peduncle considerably longer than the 1st, .- l >rd 

 joint a little shorter than the latter, flagellum exceeding in length the 

 peduncle, and composed of about 20 articulations; those in male having the 

 flagellum still more elongated, and composed of as many as 30 articulations. 

 Inferior antenna? scarcely half as long as the superior, and of the usual struc- 

 ture. Anterior gnathopoda with the propodos fully 3 times as long as the 

 carpus, and of oblong triangular form. Posterior gnathopoda moderately 

 strong, propodos oblong oval in form, and having the palm divided in front 

 into 2 small dentiform projections; those in male not very different, though, 

 as usual, attached behind the middle of the corresponding segment, and having 

 the propodos considerably larger than in female. Branchial lamellse rather 



87 Crustacea. 



