OF CONCHOLOGY. 



211 



San Juan in Central America, near Lake Nicaraugua. Many 

 other localities given by Kellett and Wood were confused, as 

 " H. Pandorce and aspersa, Sta Barbara." The latter, I am 

 told by Dr. Newcomb, was obtained at the Sandwich Is., where 

 it is naturalized. H. Pandorce is also credited to " San Juan 

 del Fuaco," which makes it probable that the place of that name 

 near Cape St. Lucas, lat. 26° 5', was the locality, as the latter 

 species is confined to the peninsula. Forbes' figure also repre- 

 sents a small, highly colored form, quite different from that of 

 the northern shell, and indicating a southern habitat. A con- 

 siderable range of variation is seen in those from the various 

 localities it is knoivn to inhabit. 



A. intercisa, W. G. Binn. As this species probably came 

 from San Miguel Island, it is very possible that crebristriafa, 

 Newc, from Clemente L, is but a variety of it, both being 

 scarcely more than extreme local varieties of KeUettii, growing 

 abnormal toward the north. This is shown by many specimens 

 of erebristriata being thin and faintly sculptured, when they show 

 a mottled coloring like the latter. Small ones have been called 

 redimita by W. G-. Binney, but differ in this coloring and in 

 having but 5| instead of 6 whorls. It is much more likely that 

 the latter was from the more often visited region oi Nickliniana^ 

 near S. F. Bay. 



A. Tryoni, Newc. This, although put by some in another 

 genus, is too near Kellettii to be properly separated. 



In my Synopsis, the phrase " |. Colors light, often palest 

 below. Inhabit dry or treeless regions, lat. 32° to 36°," should 

 have included Group XII, just mentioned, as well as the first 

 part of Group XIII, (here made § A, b.) They resemble that 

 section also in sculpture, but their affinity is plainly with Arionta, 

 as indicated by form and band, though approaching the sub- 

 tropical group of the peninsula referred by various authors to 

 Euparypha and Polymita. I have retained Carpenteri, Newc, 

 in this section with doubt, on account of the loss of the type and 

 the imperfection or disagreement of specimens identified with it 

 by Dr. Newcomb. 



It appears that Ferussac and Deshayes (Hist, des Moll., I, 

 p. 216,) considered one or more of the Californian species a mere 

 variety of A. arbustorum ! (Binney, Bibliog. part II, p. 143.) 

 Other Europeans have done the same. 



MESODON, Raf. 



Although so generally adopted, the diagnosis of this genus 

 by the author in 1831 — " differs from Helix by lower lip with a 



