APPENDIX. 351 
Brown, Il. C. B. t. 40, f. 24.—A. Borraris, Phil. N. C. 2, p. 58, 
As. t.1, f.11.—A. cor. Loven.—A. A. Br. Mol. 2, p. 461, t. 30, f. 7. 
—Sow. Th. 2, p. 780, t. 167, f. 20. Subcordate-subtriangular, sub- 
ovate, solid, inequilateral, with a fibrous silky chestnut cuticle, 
smooth, except at the acute and prominent beaks, arcuated at the 
simple ventral margin, which rises rather abruptly posteriorly ; dorsal 
edges sloping, straight; lunule very profound, lanceolate or ovate- 
lanceolate; ligament very large; hinge-margin very broad. 13. 
N. Europe. Inadequately described at p. 89. 
On Cycxas (p. 89). Consult the list of Piésidia (inequilateral 
Cyclades) in the J. Conch. 2; the Ann. Lyc. N. York, 5, Bost. J. 4, 6, 
Pr. Bost. 8, 4, Zeit. Mal. 1845, 1850, Krauss’ ‘ Sud-Afrikanischen 
Mollusken,’ Morelet’s ‘ Testacea Novissima,’ &c. 
Cyclas cornea, p. 89, t. 9, f. 15... C. lacustris, p. 89, t.14, f. 43... 
C. obtusalis, p. 90, t. 14, f. 47... C. fontinalis, p. 90, t. 14, f. 15... 
C. similis, p. 90, t. 138, £11... CO. striatina, p..90, t: 13, f 12%... 
C. Sarratoga, p. 90, t. 18, f. 16... C. nitida, p. 90, t. 14, f. 46... 
C. appendiculata, p. 91, t. 19, f. 42... C. cinerea, p. 91, t. 14, f. 44 
»« C. partumeia, p. 91, t. 14,1. 48 ... C. elegans, p91, t. 14, £493 
On Cyrena (p. 92). Consult the monograph by Deshayes (British 
Museum Catalogue); see, too, Proc. Philad. 3, Carpenter’s Mazatlan 
Shells, and Mousson’s Coquilles, &e., en Orient. 
Cyrena orientalis, p. 92, t. 13, f. 15 ... C. violacea, p. 92, t. 13, 
13... C. Woodiana, p. 92, t. 14, f.58 ... C. rotundata, p. 93, t. 14, 
55... C. Carolinensis, p. 93, t. 14, f. 56 ... C. Bengalensis, p. 93, 
. 13, f. 14... C. turgida, p. 93, t. 14, f. 50... C. Cyprinoides, p. 93, 
. 14, f. 54 ... C. Vanikorensis, p. 94, t. 14, f. 59... C. oblonga, p. 94, 
. 14, f. 53... C. Sumatrensis, p. 94, t.15, f.1... C. Australis, p. 94, 
a aye 
CYRENA TENEBROSA (t. 14, f. 2), Hinds, An. Nat. (1842), 10, p. 81; 
Sulp. p. 66, t. 21, f. 7.—Batissa t. Desh. Vener. p. 238. Oval, 
transverse, inequilateral, thick, subventricose, rather glossy, dirty 
yellowish brown; posterior third with regular deep rather distant 
sulci, elsewhere smooth or nearly so; ventral edge convex, rising 
abruptly in front; anterior slope a little retuse, the surface behind it 
a little flattened; umbones much eroded; ligament large, very pro-. 
minent ; inside whitish, purple-stained in front and ventrally ; primary 
teeth strong; lateral teeth crenated, short, the hinder one approxi- 
mate. 2...3. Freejee Isles. 
Cyrena Purtirrinarvm (t. 14, f. 60), Hanl. Z. P. 1844, p. 159. 
Very large, compressed, obovate, very inequilateral, heavy, with fold- 
like concentric sulci behind; cuticle glossy, brownish olive when 
adult, bright grass-green when young; ventral edge only slightly con- 
vex; ligamental edge somewhat sloping, forming an obtuse angle with 
ehiehick éh ee Ss 
