THE NAUTILUS. 115 



His reference to Lister was an unfortunate one as the two 

 species have nothing in common. Chemnitz in 1786 expressed 

 his surprise at the approximation. Lister's species was un- 

 doubtedly that subsequently described by Say (1817) as Limnsea 

 decisa and now known as Campeloma decisum. As the facsimile 

 of Lister's figure given by Binney (L. and F.-W. Shells, III, 

 1865, p. 43, fig. 86) is not a satisfactory reproduction of the 

 original figure, I give a photographic copy on pi. VIII, fig. 6. 



As to whether Muller's species was the Chinese species com- 

 monly known as V. quadratus (Bens. ) or the Philippine species 

 often referred to V. costatus (Q. and G.), there has been a very 

 radical and long-continued difference of opinion among con- 

 chologists. 



Mousson in 1849 (Moll. Jav., p. 62) according to von Martens 

 (Moll. Weber, 1897, p. 21) recognized that the shell figured by 

 Chemnitz as Helix angularis was different from that figured by 

 Philippi as Paludina angularis, but overlooked the fact that it 

 was the P. quadrata of Benson. 



Philippi (Abbildungen, I, 1845, pi. I, fig. 10) identified it 

 with the species described by Quoy and Gaimard in 1832 as P. 

 costata. 



Kuester(Con. Cab., Paludina, 1862, p. 26) followed Philippi. 



Reeve (Con. Icon., Paludina, 1862) referred the Philippine 

 species to angularis, which he considered distinct from costata, 

 though he remarks that the two species are very closely allied. 



Frauenfeld in 1864 (Verzeichniss, Paludina, p. 571) also re- 

 ferred the Philippine species to angularis. 



Von Martens in 1869 (Mai. Bliitt., p. 145) seems to have 

 been the first to refer Muller's species to the well-known Chinese 

 form commonly called quadrata Bens. 



Morelet in 1869 (J. de Con., XVII, p. 403) argued the ques- 

 tion at considerable length and refused to follow von Martens. 

 But he makes no reference to Chemnitz either in his synonymy 

 or in his discussion. 



Issel in 1874 (Moll. Born., p. 90) followed von Martens. 



The Sarasins (Suessw. Moll. Celebes, 1898, p. 59), while they 

 make no reference either to angularis Mull, or to quadrata Bens. , 

 refer the Celebes species to costata Q. and G. and therefore irn- 

 pliedly endorse von Martens' position. 



