476 



joint considerably curved, carpus gradually widening distally, and forming 

 below a rounded setiferous lobe, propodos fully as long as the 2 preceding 

 joints combined, and rather expanded on the middle, being nearly triangular 

 in form, palm somewhat oblique, and about the length of the hind margin, 

 from which it is defined by a well-marked, though obtuse angle armed with 

 2 successive somewhat unequal spines. Posterior gnathopoda considerably 

 more elongated, and having the carpus scarcely at all expanded below, 

 propodos about same length as the latter, and of a structure similar to that of 

 the anterior ones. The 2 anterior pairs of pereiopoda moderately slender 

 and quite alike; antepenultimate pair rather strongly built, basal joint oblong 

 oval in shape, and produced at the infero-lateral corner to a rounded lobe, meral 

 joint nearly as long as the 2 outer ones combined, and somewhat subfusiform 

 in outline; basal joint of penultimate pair somewhat expanded in its proximal 

 part, the posterior edge bulging out abruptly above the middle, that of last 

 pair less broad, though distinctly laminar, propodal joint in all 3 pairs a 

 little shorter than the carpal one. Branchial lamellae distinctly folded trans- 

 versely. Last pair of uropoda with the rami about twice the length of the 

 basal part, and lanceolate in form. Telson very large, extending nearly to 

 the tip of the last pair of uropoda, and fully 3 times as long as it is broad, 

 cleft occupying about 3 A of the length of the telson, terminal lobes obtusely 

 pointed at the tip, and each carrying 3 lateral spines and one apical. Colour 

 somewhat variable, consisting of a mixture of several tints: dark chestnut- 

 brown, pink, light yellow and pure white, arranged somewhat irregularly 

 both on the body and its appendages. Length of adult female 12 mm., of 

 male somewhat less. 



Remarks. The present species was first recorded by Colonel 



Montagu as Cancer gammarus spinosns, and was the form upon which Leach 

 founded his genus Dexamine. The Amphithoe marionis of M-Edwards is 

 undoubtedly identical with this form, and this is also the case with Ampliitlioe 

 tenuicornis of Rathke. It may be best recognized from the other species by 

 the peculiar dentiform projection of the basal joint of the superior antennae, 

 and by the form of the basal joint of the last pair of pereiopoda. 



Occurrence. The species is very frequently found along the whole 

 south and west coasts of Norway, in moderate depths ranging from 6 to 30 

 fathoms, among algae. It extends northwards to the Lofoten Isles, and 

 according to Boeck, a single specimen was found by Dr. Danielsen even as 

 far as Vadse, east Finmark. 



Distribution. British Isles (Sp. Bate), Shetland Isles (Norman), 

 Bohuslan (Bruzelius), Kattegat (Meinert), coast of France (Chevreux), Adriatic 



