PIG AN IS, Wb IE It 
SPHENODISOUS. 
Page 
Fias. 1, 2. Sphenodiscus lenticularis (Owen) ..---------------- (ES alates) SNA ate ae Me eee Sorte 71 
Fig. 1. Young of supposed typical form, natural size. See also Pl. IX. 
2. Suture of same 64. 
Moreau River,? Dakota; Fox Hills group; Coll. U. 8. Nat. Mus., No. 7754. 
WIGS Siem SPRENOCISCUSs LENSUCULLG MLS a\felicanS 0 LENO CLENS ile oy rel tps saan eet as =a en eT > 
Figs. 3, 4. Views of fragments showing lateral sutures and internal, loose younger 
yolution, natural size. 
5. Dorsal suture of one side of about same age as the one painted in on fig. 
3, natural size. 
6. Antisiphonal lobe of fig. 5, much enlarged. : 
7. First three saddles and siphonal saddle to show outlines on the next 
inner yolution to that of fig. 3, natural size. 
South Dakota; Fox Hills group; my collection. 
268 
