INTRODUCTION. ml 
the ‘Malakozoologische Blatter,’ vii. (1861); the types of these are in the Museum 
of Copenhagen, and I have been enabled to examine and figure one of them, thanks 
to the kindness of Prof. Rud. Bergh. A more complete list of Nicaraguan shells, 
including thirty-three terrestrial and eighteen freshwater species, with detailed 
observations on their occurrence and habits, from his own observation, has been 
given by Ralph Tate in the ‘American Journal of Conchology, v. pp. 151-162 
(1869-70). Some others, collected by T. Brett, in November 1877 and December 
1879, and by E. Janson, between 1870-80, were contained among the shells sent to 
me for examination by the Editors of this work. 
COSTA RICA. 
Very little was known about the land and freshwater shells of Costa Rica previous 
to the researches of the late W. N. Gabb, who enumerated forty-four species from 
that country in the ‘ Proceedings of the Zoological Society of London’ for 1879. 
Three German naturalists had, however, thoreughly explored many portions of Costa 
Rica, between 1853-66, but they paid no particular attention to the Mollusca: 
Moritz WaGNer, in 1853-54 (see ‘Die Republik Costarica, 1856); Dr. A. von 
Frantzius, in 1854-66 [see ‘ Zeitschrift der Gesellschaft fiir Erdkunde zu Berlin,’ iii. 
p. 289 (1868), ‘Archiv fiir Naturgeschichte, xxxv. (1869), and ‘Journal fiir 
Ornithologie, xvii. (1869)]; and Cart von Srepacu, Geologist, in 1864-65. To 
Moritz Wagner we are indebted for the very characteristic Helix costaricensis. ‘The 
Berlin Museum received in 1856 a number of shells, including a few land and fresh- 
water forms, collected by Dr. Cant Horrmany, a companion of v. Frantzius, who died 
in 1859, in Punta Arenas; in later times a few others were bequeathed to that 
institution by v. SeeBAcH ; and still more recently various land-shells, obtained in the 
interior of Costa Rica by Junius CarMion and van Parren, both residents at San José, 
in 1864 and 1868 [see ‘ Malakozoologische Blatter,’ xv. (1868)|, have been added. In 
1861 Dr. Morch published descriptions of one terrestrial, one freshwater, and eight 
submarine species, found by Dr. A. S. GirstED on the Pacific coast of Costa Rica (see 
‘Malakozoologische Blatter,’ vi. and vii.). In 1878 A. Boucard described seven new 
species of Costa Rican land-shells in the ‘ Proceedings of the Zoological Society of 
London’ for that year. 
Among the shells sent to me for examination by our Editors, in 1888, there were a 
few specimens collected by H. Rogzrs in Costa Rica. 
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