318 ASELLID^E. 



THE accompanying figure of this species has been made 

 from Colonel Montagu's typical specimens, described by 

 Dr. Leach, in the British Museum. Not only do they 

 differ from the J. Kroyerii of Milne Edwards, from the 

 shores of La Vendee, in their much broader form, but 

 they agree in this respect with Kroyer's figure of /. nivalis, 

 from Greenland, whilst the description of the tail given by 

 Otho Fabricius of his Oniscus marinus ("cauda subciliata 

 et extremitate incisuram vix notabilem habens, de qua 

 styli duo brevissimi, acuti, distantes") seems also to 

 accord with other British species. Dr. Leach, indeed, 

 describes the eyes in his species as being " placed close 

 together," but this character neither agrees with the type 

 nor with the descriptions and figures of Kroyer and 

 M. Edwards. The upper surface of the body is flattened 

 and marked with irregularly impressed lines. The lower 

 or outer pair of antennae are considerably more than half 

 the length of the animal. The tail is much wider than 

 long, being nearly semicircular in form, having two 

 small impressed dots a little apart towards its basal por- 

 tion ; the centre of the caudal margin has a nearly semi- 

 circular notch, with the centre of the incision slightly 

 produced into an obtuse point, on each side of which are 

 implanted the minute uropoda. 



The general colour is ashy, but very much varied in its 

 shades in dried specimens, with the front of the head 

 whitish. 



Jcera Hopeana of Costa (Faun. d. Regn. di Napoli fasc. 

 83, tav. iii.) appears to us identical with the present 

 species, agreeing with it (contrary to Signor Costa's 

 statement) in the position of the eyes ; the only apparent 

 difference consisting in the equal size and apparently 

 three-articulated structure of the two appendages of the 

 minute terminal uropodae. 



