262 



medially, gradually curving upwards to the rounded anterior ex- 

 tremity, abruptly sloping upwards and outwards to join the post- 

 doral slope. 



Umbos depressed, acute, approximate : lunule very small, but 

 deeply impressed, broadly lanceolate. The ornamentation consists 

 of rather distant, moderately elevated, rounded, concentric lira? ; 

 and of thick radial threads, separated by nearly as wide flat 

 furrows. The radial threads pass uninterruptedly across the 

 lirse, where by reason of minute crenulations on the lateral 

 faces of the threads, the appearance of punctated furrows, 

 is produced. There are six lira? within a breadth of 5 to 10 mm. 

 from the umbo ; the crenulations on the lira3 are about 35 in a 

 length of 5 mm. at a distance of 10 mm. from the umbo. 



The external colour is a pale-yellow to dirty-white, tinged here 

 and there with rosy blotches having a disposition in the medial 

 and posterior areas to run into flames. The interior is pellucid, 

 changing to opaque-white towards the margin, variegated with 

 blotches and short streaks of a reddish-colour. 



Dimensions. — Antero-posterior diameter, 21; anterior radius, 

 11; posterior radius, 10: ventro-dorsal diameter, 17; thickness 

 at a point a little dorsally to the middle line, 7 mm. A large 

 specimen measures 27*5 by 23 mm. 



Habitat. — Cast-up valves at Aldinga (Mr. Kimber); at Moonta 

 Bay (Mr. McDougall). Fresh shells dredged from 17 to IS 

 fathoms in Yankalilla Bay by Dr. Verco. 



Tellina Vineentiana, -^pec. nor. Plate xi., fig. lo. 

 . Shell small, thin, dirty-white, slightly inequivalve (the right 

 valve more convex), considerably inequilateral, the anteiior side 

 longer, irregularly ovate, narrowed and pointed behind. Orna- 

 mented with close, short, erect lamellie, becoming fewer and more 

 elevated on the post-dorsal slope, distantly radiate-striated in the 

 interstices ; the lamella? increase in numbei' by bifurcation at 

 about the middle of the valve, again to unite in pairs close to the 

 front margin. 



The front-dorsal margin is a very little convex, and only 

 slightly oblique, the post-dorsal margin being almost rectilinear 

 and very slanting ; the ventral outline is broadly arcuate, more 

 rapidly up-curving in front than behind, posteriorly it has a 

 slight incurvation. 



The umbones are small, acute, and a little elevated. 



There are two cardinal teeth in each valve, one of which is 

 bifid, and two well-develo}:>ed lateral teeth in the right valve ; the 

 pallial sinus is wide, fused to the pallial line, and extends across 

 the valve to near the adductor scar. 



