456 



moderately strong, with the cutting part not much produced, and the molar 

 expansion short and broad, palp very large, with the terminal joint much 

 expanded. Maxillae of the usual structure. Maxillipeds having both the 

 masticatory and basal lobes well developed, palp comparatively stout and 

 robust. Gnathopoda very small and feeble in structure, and nearly of equal 

 length, carpus somewhat elongated, propodos gradually widening distally, and 

 having the palm transverse. The 2 anterior pairs of pereiopoda of moderate 

 length, the 3 posterior pairs increasing greatly in size, and having the basal 

 joint much expanded. The 2 anterior pairs of uropoda nearly equal-sized 

 and very slender, with the inner ramus much longer than the outer, and 

 linear in form; last pair with the basal part quite short, rami mucroniform 

 and very unequal, the outer one being much smaller than the inner, both 

 edged with small spinules. Telson very small, unarmed and entire. 



Remaris. The present genus, established by Boeck, is here taken 



in a much more restricted sense than was done by that author, who referred 

 to it, besides the form described below, 3 other species, 2 of which 

 have already been treated of in this work as belonging each to a 

 separate genus of the family Paramphiihoidce, the 3rd being described farther 

 on as the type of another genus of the present family. As the form, 

 which Boeck expressly indicates as the type of his genus Amphithopsis, is 

 A. longicaudata. his generic name ought to be confined to that species. In 

 the restriction here adopted, the genus is a very distinct one, differing, as it 

 does, in several points very materially from the other Calliopiidffi. For 

 instance, the superior antennae are highly distinguished by the presence of a 

 distinct, though small accessory appendage, a feature not observed in any of 

 the other genera belonging to this family. Moreover the structure of the 

 uropoda is rather peculiar, and somewhat reminds of that found in the 

 ParampMihoidte. 



12. Amphithopsis longicaudata, Boeck. 



(PI. 161). 

 Amphithopsis longicaudata, Boeck, Crust, arnph. bor. & arctica, p. 119. 



Body somewhat elongated, though very much inflated, and nearly 

 depressed in its anterior part, with the back broadly vaulted. Urosorne 

 much prolonged and attenuated, occupying together with its appendages even 

 Ys of the length of the body. Cephalon about the length of the first 2 

 segments of mesosome combined, and not very deep, rostral projection some- 



