PROCEEDINGS OF THE NATIONAL MUSEUM. 177 



As to the relationship of the above form see Ball's remarks in the 

 Traiisactious of the Wagner Institute, Philadelphia, volume 3, part 1, 

 p. 122, August, 1890, and my paper on Dr. Jones' collection of South 

 American shells in Yol. xiv, Proc. IT. S. iSTational Museum, p. 323. 



Family Mitrid^:. 

 MITKA LENS, Wood. 

 Common, between tide marks. La Paz; Tres Marias. 



MITKA EFFUSA, Swaiuson. 



Rare. A solitary specimen. 



Mulege Bay (^o. 4G400, U. 8. N. M.); Dr. (labb also collected an 

 example somewliere on the Gulf side of the peninsula. 



MITRA (CANCILLA) SULCATA, 8wainHou. 



-^M. ii'Kjantea, Swaixson. + J/. 7/(ndsi). Rkkvk. -\- M. otUtiiiuf<i, SwAiN>>oN. 

 -\- M. funiculata, Reeve. 



Several specimens. San Lucas Cove (ISTos. 46405, 4640(i, U. S. X. M.). 

 The synonymy as above is given by Tryon. (Manual, Monograph of 

 Mitridn; p. 130.) 



MITRA (STRIGATELLA) TRISTIS, r.roderip. 



Numerous fine specimens. 



Mulege Bay (^o. 4G393, U. S. N. M.) ; Los Animas Bay (No. 4(3390, 

 U. S. I^. M.). 



Fisher's specimens were for the most part small <»r immature; his. 

 largest examjjle measured long. 1.17, lat. .45 inch. 



Family F A s o i o l A R 1 3> yE. 

 LATIRUS (LEUCOZONIA) CINGULATA. L a m a- 1- c, k . 



One example, Tres Marias (No. 47124, U. S. N. M.). 



Occurs also at Mazatlan in the Gulf, thence southward to Panama 

 where it has been collected by Cuming, C. B. Adams, Bridges, and 

 others. This form varies considerably in height of the spire as well as 

 in the length of the horn. It has been erroneously placed in the genus 

 3Ionoceros, Lam. {=AmntMna, Fischer, in Adams genera), also by C. 

 B. Adams in his '^ Shells of Panama," and by Chenu (Manual, tome 1, 

 p. 169, fig. 832). Calkins in his Catalogue of the Marine Shells of 

 Florida, etc., Proc. Davenport Acad. Nat. Sci., Mach 29, 1878, has 

 erroneously included this species, confounding it quite likely through 

 general similarity of name with the very different Caribbean Latirus 

 cingulifera, Lam., and further added to the confusion by including the 

 Proc. N. M. 94 12 



