54 



D. novae ho llmidiae Chenu proved after comparison to be exactl}- like our peculiar 

 specimen of cbtirneiun, but here the tendenc}- to form variceal rings is yet a little stronger, as 

 may be seen on the photograph PI. IV, fig. 13 made after a specimen of the jNIus. d'hist. nat. 

 of Paris. Here follows Chenu's description; transcribed from Pilsbrv & Sh.\rp p. 93: 



D. novaehollandiae Chenu. PI. IV, fig. 12 and 13. 



Shell subarcuate whitish, smooth anteriorly, with very minute striae on the posterior third. 

 A species of large size, white, glossy, remarkable for the fine striation of the upper (smaller) 

 end, while the larger portion is smooth with faint growth striae only. 

 Length 76, diam. of aperture 4,2 mill, (from fig.) (Chenu). 



Australia. 



The smooth form of eburneum might be considered a variet)- and then be called var. 

 novaehollandiae. 



*64. De7italium lacteum Deshayes. PI. I, fig. 21. PI. VI, fig. 35. 



1825. Dcntaliuni lacteum Deshayes, Mem. Soc. Hist. Nat. Paris, II, p. 362, pi. 16, fig. 27. 

 1866. Dentaliiun lacteum Deshayes. SOWERBY, Thes. Concli. Ill, p. 98, pi. 225, fig. 48. 

 1873. Dentalinm lacteum Deshayes, Conch. Icon. pi. VI, fig. 37. 



1897. Dentalium lacteum Deshayes. PiLSBRY & SHARP, Manual of Conch., vol. XVII, p. 99, 

 pi. 19, fig. I. 



Diagnosis. Shell cylindrical, somewhat curved, very smooth and polished, whitish, 

 milky, subtranslucent. 



Smaller than entalis, and proportionately less in diameter, invariably of a milky sub- 

 transparent color, thinner than entalis and not striated at the small end. 

 Length 30, diam. 2^\., mill, at the base. No slit. (P. & Sh. from Desh.). 



Distribution. India (Desh.); Seychelles (Mus. d'hist. nat. Paris). 



Remarks. This species has not been obtained by the .Siboga. At first I thought I 

 could identify one specimen with lactenvi but after more careful e.xamination this proved to be 

 D. sttbtorquahwi F"ischer, being transversely striated near the apex. There are in the collection 

 of the Zoological Museum of Amsterdam several specimens labelled D. lackitiii Desh. They had 

 suffered from time and dust and after having been cleaned proved to hold several specimens 

 with a striated apex. The same happened to be the case with specimens examined at the 

 British Museum and with some obligingly sent to me by Mr Joubin from the Mus. d'Hist. Nat. 

 of Paris. Of the nine Paris specimens three are longitudinally striated at the apex; of these, two 

 have a small slit on the convex side, one of which has a slight wave on the opposite side, 

 internally lined with a small rim, reminding one of forms in the group of D. soiiistriatum. 

 Deshayes in his Monograph especially mentions the fact that D. lacteum is not striated at the 

 apex, so that these striated specimens cannot belong to that species. As I have seen no fresh 

 striated specimens, I cannot judge with certainty to what species they then belong, but hold it 

 for possible that some at least may prove to be D. aciciihim. 



