1867.] MR. G. F. ANGAS ON AUSTRALIAN MOLLUSCA. 931 



Order PECTIN ACE^E. 

 Fam. Trigoniid^e. 



117. TrIGONIA PECTINATA. 



Trigonia pectinata, Lam. Ann. du Mus. iv. p. 355, pi. G7 • 



Trigonia lamarchi. Gray. 



This beautiful shell, so remarkable for the brilliant purple, silver, 

 or orange nacre of the interior of its valves, was at one time easily 

 obtained by the dredge on the " Sow and Pigs" bank, in Port Jack- 

 son. The wreck of a coal-laden vessel has, however, interfered with 

 its favourite resort, and it is now more difficult to procure than 

 formerly. Length 1 inch 2 lines. 



The valves both of this species and T. margaritacea, Lam. (from 

 Bass's Straits), are manufactured into elegant brooches and ear-orna- 

 ments by the London jewellers. 



118. Trigonia STRANGEi. 



Trigonia strangei, A. Adams, P. Z. S. 1852, p. 91. 



An extremely rare species, at once distinguished by the wart-like 

 nodules which cover the ribs. It was dredged near tlie entrance to 

 Port-Jackson Heads,' in deep water, by the late Mr. Strange, whose 

 name it bears. A few odd valves, much worn, have been washed 

 ashore at Long Bay and on the beach at WoUongong. Length 

 14 inch. 



Fam. ArcidtE. 

 Subfam. Arcing. 



119. Barbatia fasciata. 



Areafasciata, Reeve, P. Z. S. 1844 ; Conch. Icon. pi. 15. f. 99. 



A remarkably flattened species, rust-stained, and with an erect 

 bristly epidermis at the posterior end. Found under stones and in 

 the crevices of rocks at low water. Length 1 inch 9 lines. 



120. Barbatia (Acar) pusilla. 

 Area jncsilla, Sow. P. Z. S. 1833. 



A small whitish species, belonging to the same group as A. di- 

 varicaf.a. Common under stones at low water about Watson's Bay 

 and Middle Harbour. Length G lines. 



121. AnOMALOCARDIA TRAPEZIA. 



Area trapezia, Desh. Mac. de Zoologie. 



Area lobata. Reeve, P. ZTS. 1844 ; Conch. Icon. pi. 3. f. 19. 



This is the common "Mud-cockle" of the colonists. It is 

 found abundantly half buried in the mud in most of tlie sheltered 

 bays of Port Jackson, at low water, especially in Wooloomooloo 

 and Rush-cutter's Bays, and along the Parraniatta River. Length 

 3 inches. 



