190 ORTHALICUS. 



(Stiibel). Peru : Maranon (Orton). Bolivia : Middle of the 

 republic, and near the Mission of Bibosi, 20 leagues from Santa Cruz 

 de la Sierra (Orbigny). 



The thin lip and columella distinguish this species from the 0. 

 trullisatus. The typical form (figs. 6, 7) is from the Guianas, where 

 it is a widely-distributed and common shell. The specimens from 

 the upper Amazon drainage belong to a more oblong, darker colored 

 race, noticed below. It is a magnificent snail, formerly very rare ; 

 Ferussac is said to have paid 560 francs for his specimen, at the sale 

 of the Count de Latour d'Auvergne. 



It is usually known as 0. gallmasultana, Chemnitz, variously 

 written as one word, compounded with a hyphen, or as two words, 

 the latter being Chemnitz's mode. It was not originally a binomial 

 name, and even those who accept it do not extend their liberality to 

 other trinomials in the same volume of Chemnitz. The first binomial 

 name is that of Dillwyn. 



D'Orbigny distinguished two varieties : the typical form of Guiana, 

 which is shorter, more ventricose, and another discovered by him in 

 Bolivia, which is more elongated, larger, with five spiral zones and 

 black-bordered peristome. This race (pi. 47, fig. 8) which may be 

 what Pffeifer called B. meobamben&is, was met with by d'Orbigny 

 in the great humid forests of mid Bolivia, inhabited by the wild tribe 

 of Guarayos. It remains deeply buried at the feet of the trees, com- 

 ing forth upon the trunks of trees only in the rainy season, when 

 only it may be procured. He gives the 'size as 80 mill, long, 45 

 wide. It is apparently what Herr Stiibel collected on the Rio 

 Tocantins, described by Dr. von Martens as follows : It " is somewhat 

 more slender than the usual form from Guiana and Surinam, the 

 outer lip with a narrow, distinctly defined black-brown border inside, 

 parietal wall black-brown throughout, the upper half of the colu- 

 mellar margin white, lower half dark brown. Length 73, diara. 48, 

 height of aperture 48, breadth 30 mill. Approaches 0. trullisatus 

 Shuttl., but the columellar margin is thin and concavely arched, as 

 in 0. gallina sultana." 



Beck attempts to distinguish two varieties : a, cayanensis* based 

 upon the figure given by Spix, the locality of which is unknown, and 

 b, bolivianus, based upon Chemnitz's figures (which are the basis of 

 typical sultana], and those of Ferussac. The latter represents a 

 Guiana shell. It would seem that these two varietal names must 

 fall as pure synonyms of typical 0. sultana. 



