4 BOVALLIUS, A NEW ARCTIC ISOPOD. 



Aegiochus n. g. 



Derivatio: Alyfbyo;, a son of Chroaos. 



Corpus latum ovatum, valde convexum. 



Fröns siniplex, acumine procumbente, articuluin primum anten- 



uarum primi paris totum discernente. 

 Oculi grandes, ocellis niagnis. 



Anteniice primi et secundi paris longaa, flagello multiarticulato. 

 Segmenta pereii ina?qvalia; qvintum maximum, latissimum, cia- 



gulum fere formans. 

 Epimera inaeqvalia, non continua. 



Pedes prensorii robusti, ungulis magnis valde curvatis. 

 Pedes gressorii spinulosi, inteqvales. 

 Cauda longitudine thoracem ajqvans. 

 Urus lingulatus. 



The body is broad ovate, very couvex. 



The front is simple; the middle part of it totallj sepa- 

 rates the basal joints of the upper antennae. 



The eyes are large, with large ocelli. 



Both pairs of antennen are long with a multi-articulate äa- 

 gellvim. 



The segments of the pereion are unequal; the fifth is 

 longest and broadest, somewhat like a girth. 



The epimerals are unequal; they do not form a conti- 

 nuous row. 



The three first pairs of pereiopoda are robust, with strong 

 curved claws. The last four pairs are unequal in length, 

 richly provided with spines. 



The pleon and xirus, taken together, as long as the pereion. 



The urus is tongue-sliaped. 



Aegiochus is a very well defined genus, easily recognized 

 from all the other Aegid^ by the length and de.pth of the 

 fifth segment of the pereion, the broken row of the epime- 

 rals, and finally by the length of the pleon and the urus, 

 together equalling the length of the pereion. From Aega it 

 is more especially distinguished by the broader body and 

 the non-bisulcated cephalon; from Rocinela by the want of 

 a flattened rostrum and the convexity of the body; from Ali- 

 tropus it is distinguished by the large eyes and the multi- 

 articulate flagellum of the second pair of antennas. 



