MOLMJSCA— IIKI)M-;Y. 



313 



and arc parted l)y furrows of t'(|ual width. Hot 



furrows are over-run by minute and 



close concentric tlireads. Beaks acute 



and smootli. Inner ventral margin 



finely denticulate. Length, G-5; lieight, 



5 mm. 



There is a group {1 Crassalinn*) of 

 small, compressed, ridge sculptured 

 Crassatellites, distributed in Australian 

 watex's by pairs, one species long, the 

 other short. In Queensland there are 

 C. torresi, Smith, and G. rhoniboules, 

 Smith; in S. Australia, C. niicra, Verco,C. 

 producta, Verco ; in New South Wales, 

 C. semcriforme, Hedley, and C. scabrili- 

 rata, Hedley. Thanks to the kindness 

 of Dr. J. C. Verco, who forwarded 

 examples of his species, I am enabled 

 to make the following comparisons. In 

 many respects the new species is inter- 

 mediate between 0. productaf and C. 

 inicra ; | from the former it differs by 

 being shorter in proportion to height, 



by the ridges being smaller, closer and more numerous, and by the 

 secondary microscopic sculpture being much finer ; from C. onicra 

 it differs by being longer and flatter and by having the interior 

 ventral margin denticculated.§ 



It has been pointed out by Dr. W. H. Dall|| that Crassatella, 

 Lamarck, 1799, having for type C. cygnea, Spengler, is a synonym 

 of Mactra. Hence it must be abandoned in favour of Crasftafellites, 

 Kruger, 1823.!! 



A few separate valves were obtained from off Port Kembla in 

 63-75 fathoms, and off Cape Three Points in 41-50 fathoms. 



Crassatellites sbcukiforme. 

 Fig. 53. 



* Weinkauff — Conch. Cab., x., Abth. la, CrassateUa, p. 1, 1881. 



t Verco— Trans. Koy. Soc. S.A., xix., 1895, p. 92, pi. i., f. 2. 



J Id., op. cit., p. 93, pi. i., f. 3. 



§ G. aurora, Ad. & Ang. (Proc. Zool. Soc, 1863, p. 426, pi. xxxvii., 

 f. 15), from Bass Straits, is a species as yet unrecognised by local workers. I 

 venture to suggest that C. carnea, Tate, is probably a synonym of this. 



II Dall— Trans. Wagner Free Inst., iii., iv., 1898, p. 874. 



11 Kruger— Gesch. Urw., ii., 1823, p. 466. 



