IIG Mr. W. M. Tatteisall on new 



Genus BAxnvMVsis^ no v. 



Carapace evenly ronndcd in front, withont any traee of 

 rostral projection. 



Eyes set close together, apparently withont definite eye- 

 stalks, somewhat flattened and subqnadrangnlar in shape ; 

 visnal elements imperfectly developed and unpigmented in 

 preserved specimens. 



Antcnnal scale shortly lanceolate in shape, setose all ronnd. 



Moutli-or(jnns and first and second thoracic lim/js as 

 described by Sars for the genus Leptomi/sis, except that the 

 terminal joint of the palp of the second maxilla is expanded 

 at its apex and armed with numerous short stout spines, the 

 whole appendage being generally as figured by Sars for 

 Sch istonu/sis spirit us. 



Tarsus of the remaining thoracic limbs four-jointed ; nail 

 long and slender. 



Telson fairly long ; very deeply cleft, the cleft serrated j 

 lateral margins armed throughout their length with spines. 



Inner uropod witli a row of spines all along its inner 

 margin. 



Pleopods in the male exactly as for the genus Leptomysis. 



Type species, Bathymysis Helgce. 



In the general structure of the appendages of the thorax 

 (with the excejition of the second maxillae), and especially of 

 the pleopods of the male, this genus agrees almost exactly 

 with Leptomysis, G. O. Sars. The chief points of difference 

 are to be found in the second maxilla, telson, and eyes. 

 The first two of these structures are interesting as exhibiting 

 a form met with in many of the genera of the subfamily 

 Ulysince, while the eyes appear to have undergone specializa- 

 tion and reduction along lines very similar to Amhlyops, the 

 eyes of which they strongly recall, though rather smaller in 

 size. Bathymysis also bears considerable resemblance to the 

 genus Pseudomysis, G. O. Sars, but the greatly difll'crent 

 form of the telson at once distinguishes it. 



Bathymysis Helgce, sp. n. 



Carapace eovciing all the thoracic segments; evenly 

 rounded in front and at the antero-latcral corners ; without 

 trace of rostral projection. 



Pleon longer than the carapace ; the first segment equal in 

 length to the fifth and slightly longer than the subcqual 



