124 PEECY SLADBN TRUST EXPEDITION. 



379. Lithodomus plumzila, Hanley. 



lioc. Chagos Archipelago: Diego Garcia, Lagoon. 

 Originally described from West Coast of America. 



380. Lithodomus teres, Phil. 



Loe. Chagos Archipelago : Diego Garcia, Lagoon, with the preceding ; Peros Banhos, 

 Diamant, IG fathoms. 



N.B. — A few undeveloped and obscure specimens likewise occurred, which it has been 

 impossible exactly to identify. The species, especially of the nasuta type, are variable 

 and confusing, and the distribution of many is almost world-wide in the wanner seas. 

 Such occur in dredgings from Providence I., Station D 4, 56-78 fathoms, &c. 



Order PSEUDOLAMELLIBRANCHIATA. 



Family AviculidSB. 



381. Meleagrina margaritifera (L.). 

 Loc. Seychelles : Praslin I. 



Chagos Ai'chipelago : Peros Banhos, Diamant, 16 fathoms. 

 Dr. Lister Jameson has lately undertaken * a revision of the species of Pearl Oysters, 

 and I believe that those found in the above localities will come under his M. mauritice. 



382. Fteria ala-corvi (Chemn.). [Avicula, Klein.] 

 Loc. Chagos Archipelago : Diego Garcia, Barachois Maurice. 



N.B. — A pale ochreous shell from the latter locality may be Pf. ])lacunoides, Keeve. 



383. Pteria crocea (Lam.). 

 Loc. Chagos Archipelago. 



A Mauritian species, known by its bright colour. 



384. Pteria inalleoides (E,eeve). 



Loc. Chagos Archipelago : Salomon, Lagoon, 10-14 fathoms. 

 Extends in range to Australian waters. 



385. Pteria tnacroptera (Lam.). 

 Loc. Farquhar Atoll. 



386. Pteria semisagitta (Lam.). 



Loc. Amirantes : Station E 10, 22-86 fathoms, rubble of dead coral, &c. 

 The specimens are much encrusted with nuUipores, but are probably referable to this 

 species, found in the Mauritian area. 



* Proc. Zool. 8oc. Lorn]. 1901. i. pp. 372-394, figs, in text. 



