Victoriaii Mivr'ive MoUiisca. 97 



of a brown isli tiiii^e. eloiigately-eordit'oriii, medially elevated, and 

 ornamented with imhricating lamellae. The ligament is sunken, 

 narroAv. and long. Hinge area normal. The pallial sinus is broad, 

 well defined and oblicjuely ascending to about the centre of the 

 valve. The surface of the shell has four sub-equally spaced rays 

 of brown, arrow-sliaped markings. Further colouration may be 

 seen on the post-dorsal margin in four conspicuous brown macula- 

 tions. 



Dimensions of fypt- — Length, 36; breadth, 34; sectional of 

 closed valves, 16 mm. 



Localitjf. — W/estern Port, 5-10 fathorjis type taken alive; 

 dredged off Portsea, Port Phillip. 



Observation. — Under the name of D. variegata, Gray, this species 

 was recorded from Victoria by Pritchard and Gatliff, P.R.S., Vic, 

 xvi. (new series), 1903, p. 133. Careful investigation and much 

 correspondence leads us to the conviction that this is manifestly a 

 wrongful identification; and, further, that the shell is an un- 

 descriljed species. /). variegata is extremely variable; this vari- 

 ability with the figures and remarks by Reeve, Conch., Icon. vi. 

 pi. 6, fig. 33a, and Sowerby Thes. Conch. II., pt. 13, p. 675, No. 

 72, pi. U4, fig. 83, excusably leading Pritchard and Gatliff to 

 regard the Victorian sliell as another of its forms. Close 

 study, however, has revealed cliaracters, suificiently consistent to 

 warrant our separating it as a distinct species. From D. varie- 

 gata, the shell may be readily distinguished by its flatness (al- 

 though in this respect showing slight variation), by its more 

 elongated lunule and in the character of the radial sculpture. 

 Another misapplied name is D. histrio ((jimel), var., an appellation 

 recognised in South Australia. From typical D. histrio it is quite 

 distinct as depicted in the well-executed figures, by Romer. Mono- 

 granh Dosinia, p. 33, pi. vi. figs. 2. 3. 



The "Challenger" Report Laniell. p. 152, records D. Jiistrio 

 (Gmel). var. from Cape York, Flinders Passage, and Arafura Sea, 

 E. A. Smith, in his observations, remarking : " This species has 

 received several names from various authors. It is the Venus 

 anstraJAs of Quoy and Gaimard, the Artemis variegata of Reeve, 

 Artemis firafa and 1 pnticidaris of Sowerby, and perhaps the Artemis 

 scabra of Philippi. The specimens from station 187 (near Cape 

 York) and Flinders Passage resemble the variety Artemis lirata." 

 Reference to Sowerby's figure of Artemis lirata Thes. Conch., pi. 

 cxliv., fig. 85, clearly shows that our shell has been misunderstood 

 in S. Australia. D. deshayesi, A. Ad., as figured in " Challenger " 



s 



