CONTRIBUTIONS TO THE NATURAL HISTORY OF QUITO. 697 
it does not appear that any considerable number of the species 
have passed beyond its limits. The most interesting question re- 
specting their distribution, is to ascertain if any occur both on 
the Pacific and Atlantic slopes of the Equatorial Andes, and so 
far as I am informed there are scarcely any. While several of the 
valley species are found also to the south in Peru, and a larger 
number to the north in New Granada, others are common to the 
valley and the eastern slope towards the headwaters of the’ Ama- 
zon. : 
The species mentioned in the catalogue, which from the habitats 
given appear to occur on the Pacific and Atlantic slopes, are Bu- 
limulus chameleon Pfr. referred to Nanegal on the former and 
Baeza on the latter, Bulimus irroratus Rv. from Guaranda and 
Macas, and B. Popelairianus Nyst. from Bodegas and Napo. Fur- 
ther exploration may increase the species known thus to occur, 
but the difference in the land-shell faunas on the Pacific and At- 
lantic slopes on the west coast of North America, warrants the 
belief that such species are few. 
The absence in the Quito valley, and generally on the west 
coast of South America, of various New World genera is worthy 
of remark, but they belong to the faunas of Brazil, Mexico, and 
the West Indies, with which those of the west coast have a scarcely 
appreciable alliance. 
In South America generally, and the valley of Quito is no éx- 
ception, the genus Bulimus has far more representatives than 
Helix (using both generic terms in the wide sense employed. by 
Pfeiffer in his monographs), but the reverse is the case in North 
America. In the Galapagos Islands there are a number of pecu- 
culiar Bulimi, but I believe no Helices, while in the islands off the 
west coast of southern California species of Helix occur but none 
of Bulimus. On the Atlantic side of the Continents, the islands 
(Cuba, Jamaica ete,) situate on the northern margin of the Car- 
ibbean sea, with numerous species of Helix, have very few of Bu- 
limulus, while the islands on the eastern side, near to the South 
American coast (St. Lucia and St. Vincent to Trinidad) have the 
only representatives of Bulimus in the West Indies and a larger 
proportionate number of species of Bulimulus. 
Cyclophorus Crosseanus Hid.—Ecuador, Paz. 
helicinæformis Pfr. — Quito, is 
Bourciera ine os ito, Paz.: 
Fraser. 
C¥elophorus Cumingi Sow. — Quito, Paz. § 15 
elophorus Cumin w,— Quito, Paz. b yh 
it hematomma Pfr. — Quito, Paz, araqu 
Hidalgoi ardeii t e er Hh Paz. | Bourciera Fa Pir. — Cuenca, 
