24 rROCEEDINGS OF THE MALACOLOGICAL SOCIETi'. 



LIST OF THE PLEUROTOMID^ OF SOUTH AUSTRALIA, WITH 

 DESCRIPTIONS OF SOME NEW SPECIES. 



By G. B. SowERBY, F.L.S., etc. 



Bead lOth January, 1896. 

 PLATE III. 



SnsrcE the publication of "A list of Aquatic Mollusca inhabiting South 

 Australia" by Mr. D. J. Adcock in 1893, a considerable number of 

 species have been discovered, principally through the researches of 

 Dr. J. C. Verco, who has placed in my hands for identification and 

 description the PleurotomidiB found by him. Mr. Adcock and Mr. 

 Bednall have also kindly sent me a considerable number of specimens 

 for compai'ison; so that I have had pretty good material to work upon. 

 Most of the species are very small, and some are at first sight so much 

 alike that the mere sorting of them has been no little labour. The 

 generic distinctions are still very unsatisfactory, and it may be thought 

 that I have taken liberties with certain of them by placing the species 

 in what seem to me the most natural and convenient groups. 



From Mr. Adcock's list I have removed some names, and added 

 others, out of which sixteen are new, making a total of thirty-seven 

 species. 



1. SiJKCULA QpoYi, Reeve, Conch. Icon., Pleurotoma, sp. 137. This 

 is the largest species recorded of South Australian Plcurotomida). It 

 appears at present to be somewhat rare. 



2. Deillia haepulaeia, Desmoulins, Actes Soc. Linn. Bordeaux, 

 tom. xii, p. 162 ; Beeve, Conch. Icon., Fleurotoina, sp. 124. (= P. har- 

 pula, Yalenc.) Spencer's Gulf. 



3. DiULLiA Walcot,e, Sowerby, Proc. Zool. Soc. 1893, p. 487, 

 pi. xxxviii, figs. 7, 8. Spencer's Gulf ; also St. Vincent's Gulf, 

 13 fathoms (Verco). 



var. pallUla. [Nearly white, Avith a pale-buff basal zone, 



and the longitudinal ribs less prominent. With shell sand from 

 Macdonnell Bay (Adcock). 



4. Ueillia exaeata. Reeve, Conch. Icon., Plcurotoma, sp. 201. 

 St. Vincent's Gulf (Verco). 



5. Deillia dimidiata, n.sp. PI. Ill, Fig. 2. 



Testa fusiformis, tenuicula, pallida, antice balteo lato rubro, maculis 

 rufis marginato ornata ; spira acuminata, apice obtuso ; anfractus 7 ir, 

 declives, superne leviter concavi, inferne convexiuscvdi, sulcis 

 numcrosis angustissimis spiraliter insculpti, costis longitudinalibus 

 oblicpiis, irregularibus, paucis, latiusculis sed parum elevatis ; sutura 

 anguste canaliculata ; anfractus ultimus spiram fere a^quans, costis 

 indistinctis vel obsoletis, basim versus attcniuatus, hand rostratus ; 

 apertura mediocriter lata ; columella rectiuscula, tenuiter callosa. 



