474 



and without any accessory appendage, being in female much longer than the 

 inferior; the latter in male greatly prolonged. Anterior lip of the usual 

 rounded form ; posterior lip with a slight rudiment of inner lobes. Mandibles 

 very compact, and without any trace of palps. First pair of maxillae with 

 the basal lobe rather small, unisetose, palp uniarticulate, though rather large; 

 2nd pair comparatively small, with the lobes short and only setous at the 

 tip. Maxillipeds with the masticatory lobes very large, nearly concealing 

 the comparatively small and slender palps. Gnathopoda not very strong, and 

 somewhat unequal, the posterior ones being more elongated than the anterior, 

 propodos in both pairs considerably dilated in the middle, and distinctly 

 subcheliform. The 2 anterior pairs of pereiopoda quite alike both in size 

 and structure; the 3 posterior ones considerably larger, nearly equal in length, 

 and generally strongly recurved; basal joint of antepenultimate pair the 

 largest, that of last pair sometimes very little expanded, dactylus in all pairs 

 strong and recurved. Last pair of uropoda of moderate size, rami subequal, 

 and narrow lanceolate in form. Telson much elongated and deeply cleft, 

 lateral edges spinous. 



Bemarks. - - This genus was established by Leach as early as in the 

 year 1814, to include a species described by Colonel Montagu from the 

 British Isles. The genus Aiupltifltonohts of Costa must be quoted as a 

 synonym, though the name was used by other authors to include species 

 belonging to widely different genera. As above stated, Boeck regarded this 

 genus as the type of a separate subfamily, Dexamininte, chiefly on account 

 of the absolute want of palps on the mandibles. In addition to this feature, 

 the genus distinguishes itself from the 2 preceding ones by the rather different 

 longitudinal relation between the 2 pairs of antennae, by the palp of the 1st 

 pair of maxillaB being uniarticulate, and by the somewhat different structure 

 of the pereiopoda and of the telson. Boeck records 3 species from the 

 Norwegian coast, 2 of which will be described below. Of his third 

 species, D. Heibergi, I have seen no specimens, and cannot, therefore, give any 

 information upon this form. In addition to these, we know of 3 Mediterranean 

 species,viz., T). spiniventris Costa, D. anisopus Grube and D. leptonyx Grube, and 

 to these may still be added 2 species from the southern Ocean, De3'amiu<> 

 blossevdliamis of Sp. Bate, and D. Flmdcrsi of Stebbing. 



