18C8.] COMMANDER KNOCKER ON PELAGIC SHELLS. 615 



Neurosigma, g. n. 

 Typical species Neurosigma siva. 



Nearly allied to Romalaosoma, of which it is probably the eastern 

 representative ; it differs, however, in neuration. 



Body, palpi, and antennae formed and coloured as in Romal<Bosoma ; 

 the wings coloured as in some Eastern species of Argynnis : the dis- 

 coidal cells closed ; the upper discocellular of front wings extremely 

 minute ; the middle short and transverse ; the lower long, transverse, 

 and gently waved, meeting the third median nervule close to the origin 

 of the second ; the upper discocellular of hind wings short and 

 arched inwardly ; the lower long, arched outward, slightly angulated 

 in the centre, and meeting the third median nervule just beyond the 

 origin of the second. 



Neurosigma siva. 



Adolias siva, Westwood, Cab. Orient. Ent. p. JG, tab. 37. fio-, 4 

 (1847). 



Nepal. c? ? , B.M. 



Adolias covfinis of Felder (Wien. ent. Monatschr. iii, p. 182, 

 taf. 4, 1859) is identical with Abrota jumna, Moore, not A. ganga, 

 as stated by Gerstaecker. 



DESCEIPTION OF PLATE XLV. 



Pig. 1. Adolias vaciUaria, But!., p. 606. 

 2 & 9. - — decoratus, BiitL, p. 605. 

 3& 10. coeytus, Fabr., p. 607. 



4. monina, Fabr., p. 608. 



5. ^ymphcBdra canescens, Butl., p. 612. 



6. Ado/iax xtphiones, Butl., p. 609. 



7. Tannirio. svrpcrcilia, Butl., p, 610. 



8. vwUn-ia, Butl., p. 612, 



9. On Pelagic Shells collected during a voyage from Van- 

 couver Island to this country. By Commander Hugh 

 H. Knocker, R.N., C.M.Z.S. 



Having lately returned, in command of H.M.S. 'Alert,' from the 

 Pacific, where I had been sent to bring home that vessel (I found 

 her at Esquimalt in September ISti/), I now beg to send, for the 

 information of the Zoological Society, a sketch of my researches in 

 pelagic shells during my passage home. 



I conceived the idea on leaving Vancouver that, as I was going to 

 pass through the four great oceans (viz. North and South Pacific, and 

 South and North Atlantic), I might usefully try by the tow-net if it 

 were jiossible to determine where the several species began and ter- 

 minated, or whether they ran throughout the whole, or parts only, 

 of these vast extents of water ; and by the Table herewith sent it 

 will be seen with what success. 



