501 



of mesosome combined, lateral corners obtuse-angular in front, and defined 

 below Ijy a very slight sinus. Anterior pairs of coxal plates comparatively 

 smaller than in G. locusta; 4th pair not nearly so broad as they are 

 deep, and having the posterior expansion rather short and slightly serrated 

 on the edge. Last pair of epimeral plates of metasome not much produced 

 at the lateral corners. Segments of urosome somewhat convex above, and 

 having eacli only 2 dorsal, and, on either side, 2 lateral spinules. Eyes ot a 

 somewhat unusual form, being more or less distinctly instricted in the 

 middle, and sometimes approaching to a sigmoid shape, pigment very dark. 

 Superior antennae rather slender, and fully half as long as the body, 1st joint 

 of the peduncle somewhat exceeding the length of the other 2 combined, 

 flagellnm nearly 3 times as long as the peduncle, accessory appendage rather 

 elongated, and composed of about 6 articulations. Inferior antennae, as usual, 

 shorter than the superior, with the flagellum about the length of the peduncle, 

 and in male without any trace of calceolae. Gnathopoda of a similar structure 

 to those in G. locusta, except that the propodos of the posterior ones in female 

 appears somewhat shorter, and in male less obliquely truncated. The 3 

 posterior pairs of pereiopoda rather slender and elongated, basal joint of 

 antepenultimate pair with the infero-posteal corner nearly rectangular. Last 

 pair of uropoda having the inner ramus shorter than in G. locusta, not 

 nearly attaining the length of the 1st joint of the outer ramus, and armed with 

 a smaller number of spines. Telson comparatively smaller than in 

 that species, and having on each side only a single spine, besides the 

 subapical and the 3 apical ones. Body rather pellucid, and of a pale greenish 

 colour, with only a faint trace of the pinkish patches at the origin of the 

 pleopoda. Length of adult male scarcely exceeding 6 mm, that of feinale 

 still less. 



Bemarks. — This species was first described by Leach, and subseqxiently 

 figured by Sp. Bate in his well-known work from one of the type specimens 

 presex'ved in the British Museum. Li the figure, the superior antennae are 

 very short, considerably shorter even than the inferior ones, but, as suggested 

 by Sp. Bate, this may depend upon an accidental mutilation of these 

 appendages in the specimen figured. Otherwise it agrees rather well with 

 the species here described. It is very nearly allied to G. locusta, but 

 apparently distinct, dift'ering, as it does, not only in its miich inferior size, 

 but also in several other characteristics, the most conspicuous of which is 

 the peculiar shape of the eyes. It is now for the first time added to the 

 fauna of Norway. 



Occurrence. — I first found this form occurring in considerable numbers 

 in an oyster-bed on oi;r south coast, lying considerably above the level of 



66 — Crustacea. 



