by the rev. j. e. tenison-woods. 21 



On some New Marine Shells. 



By the Eev. J. E. Tenison- Woods, F.L.S., F.Gr.S., President 



Linnean Society. 



The following" marine shells were obtained by Mr. John Brazier 



C.M.Z.S., from some sif tings from the steam dredge, when 



anchored near the Sow and Pigs, Port Jackson. They are 



undoubtedly new and interesting additions to our N. S. Wales 



fauna. 



Nassa peritrema. PL 4, figs. 5, 5a. 



JV. t. parva, ovata, cmtice dilatata, lactea, siib-pellucida, nitente ; 



anfr, 5h, convex is, continue costatis, superne conspicue uni-suleatis, 



regular iter, distanter striatis ; costis angustis, acntis, sub i ml ri cat is, 15 



16 in ult. anfr. ; striis regular iter incisis ; striis 5 in tilt. anfr. sub- 



latis, cequalibus ; sutura coronata, late canaliculata ; apertura rotunde 



ovata, labro tenui, intus concavo, labio late reflexo, polito, postice tuber- 



culato ; canali contorto, cancellato. Long. 7, lat. 4, long, spiree 3%. 



Shell small, ovate, dilated anteriorly, milky white, sub-pellucid 

 polished, and shining ; whorls 5£, convex, neatly ribbed, with 

 one conspicuous sulcus above ; regularly, distantly striate ; ribs 

 narrow, acute, somewhat imbricate or over-lapping, 15 to 16 in 

 the last whorl and cut regularly into sharp, rounded edges by the 

 spiral striae. These latter are very little smaller than the sulcus, 

 rather deep, flat, and even, there are five equidistant ones on the 

 last whorl and a few closer and smaller round the canal. Suture 

 coronate and broadly canaliculate. Aperture roundly ovate ; 

 labrum thin, hollowed underneath ; one of the ribs appears like 

 a varix. The lip is polished, widely spread over the columella, 

 with a posterior tubercle. Canal twisted, canaliculate. 



This small JS T assa can only be compared in point of size to JV. 

 compacta Angas, amongst the N. S. Wales numbers of the genus, 

 but it is shorter, stouter, divested of any coloring, and sub-pellucid. 

 The peculiar, sharp, sub imbricating ribs which are regularly cut 

 into rounded eminences by the stria3, will al«o serve to distinguish 

 it. It appears not to be uncommon in Port Jackson at a few 



