Genera of Terrestrial MoUusca, etc. 205 



umella callosa, aperta, appendicula clilatafa, torta siiperne 

 munita," adding in a footnote, "Forma persimilis prsecedenti 

 (^S. dejyressa Rang), at bene distincta columella appendice 

 torta quasi duplicata, spira siibpapillatim prominula ct peri- 

 pberia magis regulari." This appendage is shown in our 

 figure (pi. ix, fig. (1) of Eawson's appendiculata. 



V. Martens (Malak. Blatt., 1868, p. 183) described Suc- 

 cinea (^Pellicula) convexa, to the dentition of which by 

 Heynemann we have already referred, giving also (phite ix, 

 figs. 12-14) copies of his figures.* One of the characters 

 of this species is said to be by its author, "paries aperturalis 

 appendicula parva, plieoe-formi munitus." 



With respect to the validity of his species, v. Martens 

 adds a note to the following eflect, — S. depressa Rang, as its 

 name implies, differs from our species by being less arched. 

 Pfeiffer writes that P. convexa is by no means the same as 

 his 8. append iculata. If the latter be identical with, depressa 

 as Fischer maintains, then Rang's figure is entirely faulty, 

 the most essential character, the process on the columella, 

 being overlooked. 



A comparison of the figures presented on plate ix, will 

 show that the Pellicula depressa of Fischer has a ribbed jaw 

 (fig. 4), and does not belong to the Succininm,^ while Pellic- 

 ula convexa v. Martens is elasmognathou"s, like . Succinea 

 (fig. 14). 



It seems to us that S. depressa of Fischer must be treated 

 as the type of Pellicula, while S. convexa belongs to 

 Omalonyx. 



Albers (ed. 2) does not include in Omalonyx or other 

 group S. depressa or S. appendiculala, mentioning them only 

 in a remark of the following purport : — 



*v. MMi-tens (Zool. Record, 1818, p. ■192), referring to Heynemann^s figure, says 

 " proving that Pellicula is not geaerioally distinct from f^uccinea." — a proposition in 

 which wo do not concur. H. & A. Adams (Genera, II, 5()S) inconsiderately remarli th; j 

 Pellicula Fischer is syn. of HelUiga, and foujuled upon FI. depressa Fischer, a new spe- 

 cies of that genus. 



t Mijreh (Jour. Conch. 18(55, p. 381) places Pellicula in his section OdontognatUa. 



