NO. 2094. MOLLVSKS OF THE OENUS RI880INA—BART8CH. 35 



tium; by Bartscli, in The Recent and Fossil Mollusks of the Genus 

 Bittium from the West Coast of America, page 401.^ 



In the preceding year Doctor Carpenter described Rissoina expansa 

 from Mazatlan, in his paper on Diagnosis of New Forms of Mollusca 

 Collected by Col. E. Jewett on the West Tropical Shores of North 

 America.^ 



The next paper dealing with members of this genus was pub- 

 lished by L. DeFolin as Les Meleagrinicoles Especes Nouvelles 

 (Havi'e, 1867). This deals with mollusks obtained from the bur- 

 rows in pearl oyster shells, which came from the vicinity of Negritos, 

 (does this mean Negros, P. I. ?) and iles aux Perles ( = Margarita 

 Island), Bay of Panama. In this paper Rissoa zeltneri is described 

 on pages 47-48 and figured on plate 5, figure 1, and Rissoa insignis 

 on pages 48-49, figured on plate 5, figures 2 and 3. 



The last species was made the type of the genus Folinia by H. 

 Crosse in his review of DeFolin's paper.^ Unfortunately, the name 

 Rissoa insignis DeFolin is preoccupied by Rissoa insignis Adams and 

 Reeve, 1850, which makes the new name given in our text necessary. 

 We do not deem it of generic rank and shall consider Folinia a sub- 

 genus of the present group. 



In 1870 DeFohn published Rissoa laurae* which must be referred 

 here. 



No additions were made until 1897, when Dr. WilUam Healey 

 Dall, in his Notice of Some New or Interesting Species of Shells 

 from British Columbia and the Adjacent Region, published Rissoina 

 newcomhi^ fromCumshewa Inlet. This, to date, forms the northern- 

 most record for the distribution of the genus on the west coast of 

 America, 



In 1902 the author described A New Rissoina from California,^ 

 calling it Rissoina halceri. 



In the same year Doctor Dall and the present writer described 

 A New Rissoina from Cahfornia,^ under the name of Rissoa Icelseyi. 



The last paper dealing with West American members of this genus 

 was pubUshed by Doctor DaU as Two Undescribed Californian Shells,^ 

 in wliich he described Alaba oldroydi, which must be considered as a 

 synonym of Rissoina Icelseyi Dall and Bartsch. This species has 

 Alahaid sculpture, but has the clawed operculum of Rissoina, a fact 

 unknown when Doctor DaU described it, as all the specimens avail- 

 able at the time were without opercula. That he was in doubt about its 



J Proc. U. S. Nat. Mus., vol. 40, 1911. 



» Ann. Mag. Nat. Hist., ser. 3, vol. 15, 1865, p. 399. 



3 Journ. de Conch., vol. 1-6, 1866, p. 218. 



* Fonds de la Mer., vol. 1, 1870, pp. 262-263. 



6 Bull. Nat. Hist. Soc. Brit. Col., No. 2, 1897, p. 14. 



• Nautilus, vol. 16, p. 9. 

 ^ Idem, vol. 16, p. 94. 



8 Idem, vol. 19, 1905, p. 15. 



