ODONTOSTOMUS. 



Length 20, diam. 10 ; aperture incl. perist. 11x3.7 ; inside 1 mill, 

 wide in the middle. 



Brazil. 



Bttliniiiliia niit/instonius var. htnifnifera ANCEY, Le Naturaliste 

 (Ser. '2), x, p. 1;"), woodcut (1888) B. copueirn Spix, var. lamini- 

 ANCKY, The British Naturalist, April, 1891, p. (53. Anctus 

 i KoHD, Proc. Acad. Nat. Sci., Phila., 1891, p. 97, t'. 1 

 (March 10, 1891); Nautilus iv, p. 134, f. 1 (April, 1891). 



I have observed no intermediate forms between A. laminiferus 

 and iinr/iostomus, and think them quite distinct species. 



Genus ODONTOSTOMUS Beck, 1837. 



Odontostontus BECK, Index Moll., p. 54 (except first species). 

 Not Odontostoma Turton, Enumeration of Marine Shells found on 

 the Devonshire Coast (1829), so quoted by Jeffreys, Brit. Conch, 

 iv, p. 108. Not Odontostoinus Cocco, Nuovi Annali delle Scienze 

 Naturale, anno 1, Tomo 2, p. 192 (1838), a genus of fishes. 



Shell rirnate, bulimoid, oblong, ovate or turreted, composed of 

 G-12 whorls, the apex vertically wrinkled, cost ate, or decussate- 

 pitted. Aperture open or obstructed by lamella? and folds, the 

 parietal lamella when present compressed and entering or twisted,, 

 never marginal; peristome expanded or refiexed, adnate to preceding 

 whorl (except in s. g. Scalarinella), the columellar lip dilated and 

 free. 



The jaw (pi. 5, fig. 30, 0. punctatisshnus) is plaited, as in Buli- 

 mutidcz generally, its component larnime shortly free at their im- 

 bricating outer edges. The teeth (pi. 5, fig. 31, 0. punctatissimus] 

 have ectocones on central and laterals, the marginal teeth with the 

 eclocone split into two distinct denticles. (Formula for 0. punc., 

 17. 11. 1. 11. 17.) 



Reproductive system (pi. 15, fig. 27, lower portion only, 0. pimcta- 

 tissimus) with all organs excessively lengthened. Retractor muscle 

 terminal on the very long penis; spermatheca globular, lying close to 

 the heart. 



Lung (pi. 15, fig. 26, O, punctatissimus) extremely long, fully 

 eight times the length of the pericardium, with exceedingly fine 

 venation, chiefly transverse, throughout, coarser near the pneumo- 

 stome and kidney. No noticeable secondary pulmonary vein, the long 

 primary vein without large branches. Kidney as short as the 



