FÜLTON : MOLLUSCAN NOTES. 237 



crenulated suture ; falcifera is almost smooth, whereas, under the 

 \Sits, falciformis is seen to be very distinotlv obli(juely striated. The 

 internal plaits are similar in both forms. Tliis coniparison has beeil 

 made with original specimens of both speoies. 



'Eo. 5. — T-he Identity of PiEEOcrcLos peestoni, Bav. & Dtz., with 



PtEROCYCLOS COCniNCUINENSIS, Pfr. 



Comparison of original examples of P. prestoni, received from 

 Colonel Messager, with the type of P. cochinchinensts demonstrates 

 that these two forms are identical. The colour of both is light 

 yellowish brown ; darker specimens with some irregulär waved 

 markings above and a peripheral narrow band of darker brown were 

 named F. predoni, var. depicta, Bav. & Dtz.; the larger specimens of 

 this variety cannot, in ray opiniou, be distinguisbed from Rhiostoma 

 morleti, Dtz. & Fisch. 



Judging by shell characters and the mauner in which various 

 authorities have placed the same forms under differeut generic names, 

 the Position of the sutural tube, upon which character the genera 

 Pterocyclos, Rhiostoma, and Opisthoporus are mainly founded, appears 

 to be of little significance. 



Synonymy of Pterocyclos cocMnchinensis, Pfr. 

 1856. Opisthoporxis cochinchinensis, Pfr., Proo. Zool. Soc., p. 337. 

 1865. Pterocyclos cochinchinensis, Pfr., Pneumonop. Vir., Siipp., ii, 



p. 37. 

 1891. P. planorbtdus, Morlet {non Lamk.), Journ, de Conch., 



vol. xxsix, p. 247. 

 1905. Rhiostoma, morleti, Dtz. & Fisch., Journ. de Conch., vol. liii, 



p. 429, plyx, tigs. 1-4. 

 1908. Pteropydos prestoni, Bav. & Dtz., Journ. de Conch., vol. Ivi, 



p. 248. 

 1908. PI prestoni, var. depicta, Bav. & Dtz., Journ. de Conch., vol. Ivi, 



p/249. 



Hai. — Cochinchina (Pfr.); Tonkin (ilorlet, Mansuy, and Messager); 

 lÄos (Massie). 



No. 6. — On De. Anton "Wagnee's Monogkaph of Helicinid^ in the 

 Conchtlien-Cabinet, 1911. 



Whilst looking through the above work I was surprised to find 

 that maiiy speoies have been omitted, and thought a list of such, 

 with the correction of some errors, might prove useful to others 

 when Consulting that monograph. Probably some of the omitted 

 species, which number more than 100, are the same as some of the 

 nuraerous new species oreated by Dr. Wagner. 



In proposing a number of new genera und sub-genera for various 

 sections of the Helicinidoe, Dr. Wagner has ignored many of 

 those of previous authorities, as may be seen by Consulting the 

 Manuel de Conchyliologie, 1887, of Dr. Paul Fischer. The sectional 

 names Oxyrhombus and Pijryodomus of Crosse & Fischer (Miss. Sei. 

 Mexique, Moll., ii, p. 399, 1893) have also been omitted. 



VOL. XI.— UAECH, 1915. 17 



