Naviculacea.j infttsohial ANiMAtcuiii:s. 405 



SxJHiRELiA rohista, (foiTnorly associated with Navicnh hifrons.) — 

 Large, elliptic, elongate, with two very strong pinnules in l-1200th. 

 Length 1-2 16th to 1-1 20th. Fossil in the siliceous meal of Finland. 



S. Testudo. — Large, ovate, obtuse, with twelve slender pinnules 

 in its length, which is l-288th. 



S. Campylodisms. — Small, ovate-elliptic ; ends equally rounded ; 

 flexuose, like Carnpulodiscus ; margin striated, with ten to twelve 

 pinnules on l-1200th. Mexico. (P. 15, f. 12, 13, 22, and 23.) 



S. decora. — Large, elongate, sides straight, extremities equally 

 acute; pinnules small, four to five in l-1200th. I^oi'th America. 



S. elegam. — Large, broad ; surface with very minute dots ; ends 

 subacute ; pinnules four in 1-1 200th. 



S. eughjpta. — Smaller, ovate, oblong, smooth ; one extremity more 

 tapering than the other, but both obtuse ; pinnules seven in l-1200th. 

 Mexico. 



S.fexuosa. — Larger, flexuose; pinnules four to five in l-1200th 

 (only a fragment examined) ; approaches Camj^i/Iodiscus. Mexico. 

 (P. 15, f. 11.) 



S. Ilicrocora. — Yery small, smooth, lanceolate ; ends short, acute, 

 equal; pinnules marginal, ten in 1-1 200th. Cayenne, Mexico. 



S. myodoti. — Small, nan-ow", elongate, rather curved; ends rounded; 

 pinnules small, closely set, and giving the margin a toothed appear- 

 ance, six to seven in l-1200th. Mexico, 



S. ooplmna. — Larger, view on the sides ovate, plicate-undulate; 

 one end widely rounded, the other tapering, but obtuse ; there are 

 five transverse but obscure plicae (undulations) ; pinnae small, six in 

 1 -1200th. Falaise and Mexico. 



S. Peruviana. — Yery large, but narrow and elliptic-lanceolate; 

 extremities equally obtuse ; pinnules very small, faint, about twelve 

 in l-1200th. Peru. 



S. Begiila. — Small, linear, sides straight, with six bands, ends 

 cuneate ; pinnules ten in l-1200th; almost obsolete. Mexico. 



S. (?) paradoxa. — Small, and not pinnate on the navicular sides, 

 linear-elongate, elliptic, and ends rounded. Length l-576th. 

 Caltanisetta, Sicily. 



S. rhomloidea. — Smooth, not pinnate on the sides, which are rhom- 

 boid; ends obtuse on back, linear. Length 1- 744th. Caltanisetta. 



