557 



plates, the unusually strong build of the urosome, and by the structure of the 

 gnathopoda and pereiopoda. 



Occurrence. - - I have not myself met with this form, but it is stated 

 by Boeck to occur in the Christianiafjord. The figures here given are from 

 French specimens kindly sent me by M. Chevreux. 



Distribution. British Isles (Sp. Bate), Bohuslan (Malm), Kattegat 

 (Meinert), Baltic (Zaddach), coast of France (Chevreux), Adriatic (Grube). 



Gen. 6. Gammaropsis, Lilljeborg, 1854. 



Syn: Euiystheus, Sp. Bate. 



Autonoe, Bruzelius (part). 



Body slender, with the coxal plates of moderate size; 4th pair of 

 same shape as the preceding pair; 5th pair with the anterior lobe deeper 

 than the posterior. Cephalon with the frontal part somewhat projecting, 

 lateral corners more or less produced, postantennal ones well defined, and 

 far behind the former. Eyes well developed and rather large. Antennee 

 slender, nearly equal in length, and fringed posteriorly with fascicles of 

 slender bristles, the superior ones with the last joint of the peduncle much 

 elongated, and the accessory appendage distinctly developed. Anterior lip 

 more or less produced in front. Mandibular palp very large, with the 

 terminal joint lamellarly compressed, and clothed with numerous very long 

 bristles. Oral parts otherwise normal. Gnathopoda more or less unequal, 

 the anterior ones being rather feeble, and of the very same structure in the 

 two sexes, the posterior ones, as a rule, considerably larger, and in male 

 much more strongly built than in female. The 2 anterior pairs of pereiopoda 

 normal; the 3 posterior pairs moderately elongated, and having the basal 

 joint more or less expanded; the last 2 pairs about equal in length. Last 

 pair of uropoda of moderate size, with the basal part somewhat elongated, 

 and the rami narrow linear. Telson not very large, rounded. 



Remarks. The present genus, established by Prof. Lilljeborg, is 

 chiefly distinguished from the preceding genera by the comparative^ large 

 size of the eyes, the subequal and densely setiferous antennae, the peduncles 

 of which are very much elongated in proportion to the flagella, the unusually 

 elongated mandibular palps, and finally, by the structure of the gnathopoda in 

 the two sexes, and by that of the last pair of uropoda. The genus Eiiri/*tlt< no" 



74 Crustacea. 



