333 



ON A SMALL COLLECTION OF MOLLUSCA FEOM 

 TIEERA DEL FUEGO. 



By Edgak a. Smith, I.S.O. 



Bead \Gth June, 1905. 



The specimens under consideration formed part of the zoological 

 collections brought home by Captain Eichard Crawshay from Tierra 

 del Fuego a few months ago. Considering the smallness of the 

 collection it is interesting to find so large a proportion of novelties. 

 This is accounted for from the fact that the island has never been 

 thoroughly investigated for mollusca. The Wilkes Exploring Ex- 

 pedition (1838-1842) discovered a number of new forms, and the 

 French Mission Scientifique du Cap Horn (1882-1883) collected a few 

 more. Dr. R. 0. Cunningham, during the voyage of H.M.S. " Nassau " 

 (1866-1869), and Dr. R. W. Coi)pinger, dunng the survey of H.M.S. 

 "Alert'' in 1879-1880, made considerable collections of mollusca in 

 the Straits of Magellan and Southern Patagonia, although not actually 

 on the shores of the island. No special list of the mollusca of Tierra 

 del Fuego has hitherto been published,^ so that the following may be 

 regarded as the first instalment of such a catalogue. Captain Crawshay 

 made no attempt at systematic shell-collecting, but merely picked up 

 the few specimens that he came upon by chance. Conse'quently the 

 small number of species obtained gives practically little idea of the 

 probable richness or poverty of the fauna. The land shells at present 

 known from the main and adjacent islands consist of about eight very 

 small Helicoids and two or three species of Succinea. The only fresh- 

 water forms are two species of Limnma, two species of Acyrogonia, 

 a group allied to Limnoia, and one or two species of Chilina^ besides 

 that now described. This genus has not previously been recorded 

 from the main island. 



Among the marine fonns occurred a single worn shell (Fig. i), of much 

 interest, apparently belonging to a new genus. It has a subfossilized 

 appearance, but my colleague, Mr. R. Bullen Newton, has failed to 

 recognize it as a palaeontological specimen. The rest of the collection 

 consists of well-known Patagonian and Magellanic forms, such as 

 Trophon, Bullia, Photinida, Nacella, Modiolarca, etc. 



With reference to the localities quoted in the following pages, 

 Captain Crawshay has supplied these notes: — 



" ' San Sebastian Beach' refers to the sea-shore of San Sebastian 

 Bay. _ ' Rio McClelland ' has a wider sense than merely the mouth of 

 the river, and refers rather to the southern shore of Useless Bay, 

 working from the Rio McClelland as a base. 



1 Most of the known species, however, are quoted bv Mabille and Rochebrune in 

 their account of the Mollusca of the Mission Scientifique du Cap Horn. 



