10 ME. E. J. MIEES ON THE IDOTEID^. 



vergent to the subacute distal extremity of tlie postabdonien. 

 Head enlarged ; its lateral margins divided by a suture into two 

 lobes, behind which tlie eyes are situated. Postabdomen large, 

 consisting of four or five distinct segments. Antennules some- 

 what elongated. Antennge rather short, but with a well-deve- 

 loped articulated flagellum. Mandibles robust. Maxillipedes 

 with a 3-5-jointed palpus. Epimera considerably developed, 

 and some or all evident in a dorsal view, the posterior three 

 pairs prolonged backward at their acute postero-lateral angles. 

 Legs robust ; those of the three anterior pairs thrown forward, 

 with the dactylus reflexible and tlie penultimate joints or palms 

 dilated, the dilatation usually greatest in the first pair. Oper- 

 culum with the basal plates marked with a raised line running 

 close to and nearly j^arallel with the inner margins, but without 

 an oblique line on their outer surface ; beneath the terminal 

 plates is a very small oval lamella, which is the outer ramus of 

 the modified uropoda. 



Mr. Harger, in his description of GMridotea, first indicated the 

 natural limits of this genus, and that it would include the long- 

 known Idotea entomon and I. SaMni (Am. J. Sci. & Arts, xv. 

 p. 374, 1878). By many, and even some recent, authorities these 

 species, notwithstanding their obvious distinctness from other 

 members of the family, have been included in the genus Idotea. 



I have not been able to consult Haller's description of Saus- 

 sureana, and the citation of this genus as synonymous with 

 Glyptonotus must be considered doubtful. According to the 

 generic diagnosis quoted by Dr. Bertkau (Archiv f. Naturgesch. 

 xlvi. p. 271, 1880), the three anterior thoracic legs are chelate, 

 body linear (an approach to this form is exhibited in young 

 G. SaMni). The species, which its author does not name, only 

 differs from Glyptonotus in its very short antennge, and is from 

 Labrador. 



In its geographical range Glyptonotus appears to be confined 

 to the colder temperate, arctic, and antarctic seas. 



The species of this genus may be distinguished as follows : — 

 a. Epimera distinct only on tlie three posterior segments. 



Thoracic segments with a median line of tubercles ; terminal 

 postabdomiual segment longitudinally carinated. 



1. G. antarcticus, Eights. 



