226 



Habitat. — Dredged alive in numbers in mud at 10 

 fathoms, off Banks Islands, and at 15 fathoms in Wallaroo 

 Bay, Spencer Gulf. 



Glycimeris pectinoides, Deshayes. PI. xxviii., tig. 4. 



PectuncuJus pectinoides, Deshayes, Cuv., Regn. Anim (Fortin 

 and Masson's ilhistrated edition), Moilusques, pi. Ixxxvii., f. 8. 

 Illustrations Conchyliologiques, Chenii, Fectuiiculus, pi. ii., f. 2: 

 Reeve, Conch. Icon. Pectuncaliis, pi. viii., f. 44. Pectunculus 

 gealei, Angas, Proc. Zool. Soc. Lond.,1873, p. 183, pi, xx., f. 5. 

 Type locality, off Port Macquarie, N.S. Wales, Tate, Trans. 



Roy. Soc. S. Austr., 1891, vol. xiv., part 2, p. 268; (Glycymerisj, 

 Tate & May, Proc. Linn. Soc. N.S. Wales, 1901, vol. xxvi., part 

 3, p. 436. Pectunculus flaheUatus, Ten, Woods, Trans. Roy. 

 Soc, Vict,, 1878 (1877), vol. xiv., p. 61, 62. Type locality, Victoria 

 and Tasmania: Tate, Trans. Roy, Soc. S, Anstr., 1886, p, 103, 

 No, 134: (Glycimeris), Pritchard and Gatliff, Proc, Roy. Soc, 

 Vict,, 1904, vol, xvii, (n.s.), part i., p. 243. Pectunculus orbicu- 

 laris, Angas, Proc. Zool. Soc. Lond., 1879, p. 420, pi, xxxv,, f. 9. 

 Pectunculus beddomei, E, A. Smith. Chall., Zool., 1885, vol, 

 xviii., p. 255, pi, xviii., f. 1, lb. 



Our South Australian shell was first recorded by Tate 

 as P. flaheUatus, Ten. Woods, in 1886; later as P. gealei, 

 Angas, in 1891, The species figured by Chenu as P. iKcti- 

 tioides, Deshayes, and described and figured by Reeve as P. 

 pectenoides, cannot be distinguished from a half-grown ex- 

 ample of our shell. Reeve gives "Bay of Panama" as its 

 locality, and says: — ''After receiving from M. Deshayes the 

 example of this species, originally described by him, Mr. 

 Hinds supplied me with finer specimens from the collection 

 of Captain Belcher." The habitat is far distant, but our shells 

 appear conspecific. 



It is not a common shell on our beach, but is fairly 

 abundant in deeper water. It has been dredged in Spencer 

 Gulf from Wallaroo Bay to Thorny Passage, in Investiga- 

 tor Strait, in St. Vincent Gulf, and through Backstairs Pas- 

 sage as far as Beachport, It has been taken alive at all 

 depths between 8 and 30 fathoms, but is most numerous 

 about 22 fathoms. Valves have been secured at all depths 

 explored up to 150 fathoms off Beachport in decreasing quan- 

 tities. 



It is a very variable shell. When young it has an orbi- 

 cular shape, being rather longer than high, and having a 

 long, straight dorsal border. As it grows, it becomes higher 

 than long, and its dorsal border is proportionally much 

 shorter. It generally remains almost symmetrical : rarely it 

 becomes quite decidedly oblique. 



It may vary in obesity. One example, 41 mm. high, may 

 be 30 mm, in section ; another, 37 mm, high, may be only 

 20 mm, in section. The latter are of the compressed P. bed- 



