194 Mr. W. H. Benson on new species of Cyclostoma. 



Taking up the thread dropped east of the Burhampooter river, 

 and descending through the Burmese territories and the Malayan 

 peninsula, we find at Tavoy and Tenasserim, Pulo Penang and 

 Malacca, C. aurantiacum, Schura. {pernobile, Gould), sectilabrum, 

 Gould, Perdioc, Sow., Cantori, nobis, semidecussatum and Tuba, 

 Sow. ; and at Singapore, near the extremity of the peninsula, C. 

 aquilum, Sow., and rostellatum, Pfr., Zeitschr. No. 1, 1851; in 

 the Siamese territory, C. Siamense, Sow. ; in Cochin China, C. 

 gibbum, and stenostoma, with Pterocyclos anguliferus, Souleyet ; 

 and in Southern China, C. punctatum, Grateloup (irroratum, 

 Sow.), rightly attributed by Sowerby to that country, whence I 

 have received it through Dr. Cantor, but assigned by Grateloup 

 to Ceylon. At Pulo Susson, near Penang, a very distinct species 

 of Pterocyclos was taken by Dr. Bland ; and on the same island 

 Dr. Cantor procured the small pale variety of C. nitidum, Sowerby, 

 a species which is very widely spread, appearing in the Nilgher- 

 ries as well as in Java and the Philippine islands. Pterocyclos 

 biciliatus, Mousson, of which only an imperfect specimen has 

 been observed, belongs to Burmah. 



Sowerby has referred C. undulatum to Bengal. I have never 

 heard of its existence there, and I obtained a specimen at the 

 Mauritius from Sir David Barclay, from the shore to the south 

 of the harbour of Port Louis. C. cinctum, Sowerby, is also cited 

 by that author as an East Indian shell. It has all the characters 

 of a group from the islands of East Africa, and Petit gives Ma- 

 dagascar as the habitat. Sowerby and Petit are equally at vari- 

 ance regarding the habitat of another insular African form, C. 

 filosum, Sow., who calls it a rare East Indian shell. Sir D. Barclay 

 presented me with a specimen taken in the island of Rodriguez. 

 C. Belangeri, Pfr. {aurantiacum, Desh.), is noted as found only 

 in the environs of Pondicherry. The type is oceanic, and I have 

 lately found two undoubted specimens among shells sent from 

 the Mauritius as C. Rangii. May it not have been imported 

 into the French Indian settlement, with plants, from that island ? 



Great diversity of opinion exists regarding the true C. planor- 

 bulum of Lamarck. A gigantic species which I observed last 

 year, in the Senkenberg Museum, at Frankfurt am Main, ap- 

 pears to me to agree better with the figure copied in pi. 29. f. 18 

 of Kuster, than any other form attributed to it. It is labelled 



paper in the 'Annals ' for 1848, except in recognising correctly Pt. angu- 

 liferum, Souleyet, from Cochin China as a separate species, and adding some 

 forms since described. Nine true Pterocycli are admitted, only one (C. 

 spiracellum, Ad. and Reeve) being doubtful, and two species of. the trad- 

 itionary form Myxostoma of Troschel., Dr. Bland's two undoubtedly 

 distinct species would, if accessible for description, increase the number of 

 true Pterocycli to eleven. 



