THE NAUTILUS. 117 



recognizably distinguished from other snails by the three white 

 angles or perceptibly raised, parallel, transverse stria?, which 

 are seen upon the whorls. Because it is seen to be thus some- 

 what angular in its formation and aperture, our renowned 

 Miiller has called it Cochleam angularem. It lives in the Chinese 

 rivers, has a length of only sixteen lines and is certainly un- 

 known at present to most lovers of shells; hence it is rare and 

 uncommon. I do not comprehend how Miiller could find it 

 like the figure of Lister, tab. 127, no. 27, which he refers to in 

 his Hist. Verm." 



Dr. Pilsbry adds: " Miiller's angularis does not depend upon 

 Lister, he notes a discrepancy in size. I have therefore had 

 Chemnitz's figures copied. Nearly all of Miiller's exotic shells 

 were from the Spengler collection, and there is every reason to 

 believe that Chemnitz figured one of the type lot from the same 

 collection." 



It is only necessary, in addition, to compare Chemnitz's fig- 

 ures with a typical specimen of quadrnta Bens, from China 

 (Coll. Walker, No. 46135) figured on pi. IX, fig. 10, and Quoy 

 and Gaimard's figures of the Celebes type of their costata (pi. 

 VIII. figs. 9-10) to come to the conclusion reached by von 

 Martens. 



Morelet's remark (1. c. p. 407) that Paludina quadrala is dis- 

 tinguished by its more elongated form, less shouldered spire 

 and a proportionately smaller aperture is a very apt statement 

 of the difference between Chemnitz's and Quoy and Gaimard's 

 figures and practically convicts him out of his own mouth. 



To which of the many described forms of the protean Chinese 

 species, angularis should be referred is "another story" and 

 outside the purview of this paper. But there can be no doubt 

 but that Miiller's specific name should be associated with the 

 Chinese rather than with the Philippine species. 



VIII. 



VIVIPARUS COSTATUS (Quoy and Gaimard . PI. VIII, figs. 9-13. 



PL IX, fig. 6. 



Paludina costata Quoy and Gaimard. Voy. Astrolabe, III, 

 1832, p. 170, pi. 58, figs. 1-5. 



