440 MOLLUSCA. PSAMMOBIAD.E. Astartj;. 
it is known in the north of Scotland by the trivial name of “ Brmon circular 
furrowed mrtfiern CocJcle^^^ — a descriptive epithet we have not heard of, and 
which seems somewhat different from the usual provincial appellations. 
BQl. A, Danmoni£B.^^he\[ transversely ovate, with strong, 
regular, equidistant, concentric smooth ridges. 
Venus Dan. Mont. Test. Brit. Sup. 45. t. xxix. f. 4. — Crassina sulcata, 
Turt. Biv. Brit. 131. t. xi. f. 1, 2. — English and Scottish coasts. 
Length an inch, breadth an inch and a quarter ; shell white, with a dark 
brown cuticle ; beaks nearly central, inclining, below which is a lanceolate 
depression ; margin within glossy and crenulated ; teeth, two in each valve. 
* Margin plain. 
50S. A. Scotica. — Shell transversely ovate, with strong, re- 
gular, equidistant, concentric, smooth ridges. 
Venus Scotica, Maton and Raclcett^ Linn^ Trans, viii. pt. 1. t. ii. f. 3. — 
Mont. Test. Brit. Supp. 44— Crassina Scotica, Turt. Biv. Brit. 130. 
t. xi. f. 3, 4— Various parts of the coast, from Devon to Zetland. 
Length /gths, breadth an inch ; white with a brown cuticle. It is princi- 
pally distinguished from the preceding by the greater compression of the 
ventral margin, the shortness of the lunule, and in the inside being less 
rough, and the margin entire. 
503. A. compresm. — ^Shell subtriangular, rounded in front ; 
beaks very prominent, and inclining ; obsoletely and irregularly 
sulcated transversely, 
Venus compressa, Mont. Test. Brit. Sup. 43. t. xxvi. f. 1 — Maton and 
Rackett., Linn. Trans, viii. t. ii. f. 2 Cyprina compressa, Turt. Biv. 
Brit. 136. t. xi. f. 20-23 — Coast of Scotland. 
Diameter about half an inch ; shell white, with a brown cuticle ; cartilage 
slope but little rounded ; the depression in front of the beaks sudden. While 
the figure in the Linn. Trans, above quoted belongs to this species, the de- 
scription is that of A. sulcata. I possess dead valves from St Andrew’s Bay 
upwards of an inch and three-tenths in length. Is this distinct from Cms- 
sina semisulcata of Dr Leach, Annals of Philosophy, xiv. 204. ? Even by the 
taid of authentic specimens, I have failed to procure a specific difference. 
EXTINCT SPECIES. 
1. A. lurida Transversely oblong, convex, depressed, with many trans- 
verse undulations ; lunette elliptical, sharp ; margin crenulated within, near- 
ly straight ventrally. — Sower. Min. Conch, t. cxxxvii. f. 1 . — Inferior Oolite. 
2. A. e^6'^ram.--Transversely oblong, convex, depressed, with many small 
transverse costse, lunette cordate ; margin crenulated within— Min. 
Conch, t. cxxxvii. f. 3.-— 7w/mor Oolite. 
3. A. Subcordate, acuminated, gibbose, with small transverse 
costae; lunette eordate; margin entire within.--^S'oicm Min. Conch, t. cxxxvii. 
X 2.-m^Upper Oolite. 
4. A. p/awa.~Mearly orbicular, depressed, surface plain ; lunette elongated, 
acute, deep ; margin entire.— fihtcer. Min. Conch. 170. f. 2.~^Crag2 
5. A. obliquata Ohovate, transversely depressed ; with many oblique con- 
centric striae upon tfie surface ; margin crenulated— Min. Conch, 
t. clxxix, f. 3— In Crag. 
