204 Christmas Island. 



characters renders this specimen of no account for determination 

 purposes. Found in a cream-coloured limestone containing corals 

 and other structures. The front or apertural part of the specimen 

 is embedded in matrix. 



Locality. — Top of first inland cliff, about 300 feet above sea-level. 



Numher on specimen : 951a. 



Examples : 1 . 



INDETERMINABLE SPECIMENS. 



First. — A fragment of white limestone weathering a slaty colour, 

 with remains of a Gasteropod cast, probably of Trochoidal affinities, 

 l)ut not identifiable. 



Locality. — North coast, about 50 feet above the sea-level. 



Number on specimen : 1043. 



Examples ; 1 . 



Secondly. — A mass of light-coloured limestone contains several 

 small forms of Gasteropod shells whose structures, having mostly 

 dissolved away, leaving mere casts or impressions, are not capable 

 of accurate determination. Among some of the shells represented 

 in the block appear to be Nassa and a number of Cerithium-YikQ 

 forms with a granular ornamentation, probably belonging to the 

 genus Bittium, etc. 



Locality. — Top of first inland cliff, about 300 feet above sea-level. 



Number on specimen : 951. 



Examples : One block ; composed entirely of small Gasteropods. 



MOLLIJSCA : LAMELLIBRAIN^CHIATA. 



Genus VENUS, Linnseus, 1758. 

 Systema Naturae, 1758, lOtli ed., p. 684. 

 Type. — Venus verrucosa^ Linnaeus. 



Venus verrucosa, Linnaeus. 



Venus verrucosa, LinnaRUs: Systema Naturae, 1758, lOth ed., p. 685 ; Philippi, 

 J-Lnum. Moll. Sicilise, 1836, vol. i, p. 43 ; Komer (E.), Kritische 

 Untersuch. Venus, 1857, p. 26 ; Fischer (P.), in Tchihatcheff's 

 " Asia Mineure," 1866-69, volume on ' Paleontologie,' p. 365. 



Description. — Shell sub-cordate and thick ; sculpture exhibiting 

 nearly equidistant concentric ridges, with a series of intermediate 

 fine and closely-set striations ; the ridges are tubercled or verrucosa 

 at the sides ; a ribbed structure radiating from the beaks lies 

 immediately below the outer coating with the concentric ridges, 



