1% SKl'IA. 



oblong, elongate, straight, compressed, wrinkled above, obtuse 

 anteriorly, winged posteriorly. Length. S inches. 



W. Coast of Africa. 



S. iXKKMis. Hasselt. IM. <>!. fig. 4'2X; PI. '.:>. figs. 4-24-4^.). 



P>odv oblong, smooth, blunt behind : lins narrow in front, 

 rather wider behind, beginning behind the front edge ; cups of 

 jmus small, the rings entire on the narrow, and finely toothed on 

 the broad edge: tentacles long, slender, without any distinct 

 club, slightly impressed at the top externally, the cups very 

 minute or entirely wanting. Shell oblong, elongate, straight, 

 rounded, acuminate in front, hinder end not b'eaked above, ex- 

 panded and produced into a cart ilage behind; convex beneath. 



with a strong central groove. 



India; China. 



I include the two species ,S'. tihii'nxi* and /&. micrOCheirUS of 

 Gray, as I do not find any appreciable difference: I also include 

 S. affim* (tig. 4-2r>) and S. Tourannenti* (figs. 4:27 t-J'.i) of Sou- 

 levet. from ( 'ochin ( 'hina. which appear to me to be t he young 

 of the same species. 



f f f Shell oblong, rounded behind, beaked. 



S. ROSTKATA. d'Orb. PI. j:j. tigs. M()~4:i'2. 



Body thick, i-ounded. narrow bt-fore. obuise behind : lins thick, 

 narrow in front, dilated behind; arms elongate, slender, unequal, 



order of length 4. .">. '2, 1. the cii|>s spherical, with very small 

 smooth-edged rings; tentacles lanceolate, with very small numer- 

 ous equal-si/ed cups in many lines and with toothless rings. 

 Shell ovate, oblong, t uberciila rly wrinkled, depressed, broader 

 in the middle, narrow behind, with an elongated, compressed 

 beak : convex in front, concave and wit h a diaphragm behind. 



Length. 1 1 inches. 



Indian Ocean ; Australia. 



With remarkable similarity between t he shell of 1 his specio 

 aild that of N. unilciitn. t here is some difference in the outline 

 of t he animal and in t he rings of t lie suckers. I include S. Blain- 

 rilli'i. the name of which was changed to S. Indira, because the 

 former was preoccupied by Deshayes for a fossil species; the 

 latter however, proves to be a synonym, so t hat S. Ilia inmllei. 



