100 : 
MOLLUSK FAUNA OF THE GALAPAGOS ISLANDS. 
~ The molluscan fauna of the Galapagos Islands, according to the 
summary resulting from the Albatross collection in the U.S. 
National Museum, and the species previously enumerated in the 
lists of various authorities and collectors, foots up 288 species 
and thirty varieties. Of these, fifty-nine collected by the Alba- 
tross were not before reported from these islands. Thirty-one 
species and seventeen varieties of land shells, principally Bulimi, 
form a part of the above total. The mollusca of the Galapagos, 
both marine and terrestrial, are distinctly West American in 
‘their characteristics; a few species suggesting Antillean forms. 
or more are new, and have been described by Mr. Dall and the 
writer. The land’shells exhibit exceeding variability, and many 
‘Species not recognized by me, are apparently based on varietal 
forms. The general aspect of the land shells, as well as the 
character of their variation, indicate their relationship to the Buli- 
moid forms of Chili, and Peru, and point to the South American 
‘main land as the region of their origin. Several deep water 
- Species have been described by Dall, and more remain to be ex- 
‘amined and determined. 
‘The Galapagos Islands seem ‘to be the metropolis of many 
marine species that have hitherto been found sparingly on the 
main land. Among these are Conus Fergusoni, Latirus iubercu= 
‘ daius, Purpura planospira, Cassis tenuis and Cyprea migropunc= 
tata; while Conus brunneus, Conus purpurascens, Murex princeps, 
Oniscidea tuberculosa, Cerithium maculosum, and Nerita scabri= 
costa, the latter of large size, are quite common. 
_ While the Pelecypoda are represented in the list by sictparoe 
Species, the number of individuals seems to be rather small. The 
Tectarius of the Littorinidae, also occurs. The detection of a 
Species of Zonites is worthy of special attention. 
ROBERT E. C. STEARNS, 
Guano found on ‘leis aids in Peru, etc., which was ‘considered 
‘the excrements of birds, is now considered to be.an accumulation 
of the bodies of animals and plants, mostly Diatomacez, upheaved 
the bottom of the ocean by volcanic agency. 
A smal number also appear to be local; of these some dozen. 
Onchidiide are represented by two forms both indigenous, and 
