646 E. B. BRANSON 



referred to it. They are much larger than the type, but appear to 

 agree with it in every other respect. The present location of the 

 type was not ascertained. 



Janassa unguicula Eastman (PI. II, Figs. 7-1 S) 

 1903. Janassa unguicula Eastman, Bull. Mus. Cotnp. ZoSl., XXXIX, 173-74, 



PL II, Fig. 13. 

 1903. Janassa unguicula Woodruff, Ncbr. Geol. Sure, Vol. II, Part II, p. 288, 



PL XVIII, Fig. 8. 



Classed together under this species are 25 teeth that would 

 probably be referred to two genera and four species if they were 

 isolated. Fig. 7 of PI. II stands at one end of this series and Figs. 

 8 and 9 at the other end, and the series arranged to show small 

 variations would be Figs. 7, 17, 16, 14. 12, 10, 9, and 15. 



All of the teeth have part of the root missing but the one shown 

 in Figs. 13 and 14 is nearly complete. The teeth range in width 

 from 11 mm. to 19 mm., and one imperfect tooth seems to have 

 been 25 mm.; the length is indeterminate; the thickness at the 

 thickest part is 2 mm. to 6 mm. In every specimen the cutting 

 edge is more or less worn and rather dull. The edge ranges from 

 almost straight to bilobed, with three sharp cusps, the lateral ones 

 much larger than the other. Numerous dentine tubules run length- 

 wise a short distance below the surface of the tooth and turn out- 

 ward almost at right angles near the surface. Near the cutting 

 edge the surface of many of the teeth is worn or eroded until the 

 longitudinal tubules are open, as shown in Figs. 7, 10, 14, and 17, 

 and on the rest of the surface the vertical tubules open, giving a 

 rinely punctate appearance. Teeth that are unworn are not 

 punctate at the surface. 



Three teeth have small longitudinal ridges on the posterior 

 face, as shown in Fig. 8, but as some that agree with these in other 

 respects lack the ridges their presence is not considered of much 

 value in classification. 



The anterior surface of the parts preserved is strongly and 

 regularly convex and the posterior face regularly but much less 

 strongly concave. The mark of the overlapping tooth appears on 

 almost every specimen and is shown in nearly all of the figures. 

 Fig. 10 shows overlap to near the cutting edge, while Fig. 17 has 



