PLATE VIII. 



Naticella transversa. Page 171. 



1, la.— Vertical and lateral views of a specimen enlarged about three 

 diameters. From a squeeze. No. 6, Dozier collection. 



Strophostylus permianus. Page 170. 



2. —A large specimen, showing growth lines. 



2a. — Another specimen, somewhat distorted, natural size. No. 71, 

 Whitehorse collection. 



26.— Another compressed individual, enlarged. No. 72, Whitehorse col- 

 lection. 



2c.— Base of another specimen, showing aperture. No. 102, Whitehorse 

 collection. 



Trepospira haworthi. Page 166. 



3. —Specimen showing approximate form of the apertures as shown in 

 section of body whorl near the mouth of the shell, in the matrix. Enlarged. 

 No. 59, Whitehorse collection. 



3a. —Another individual, showing body whorl. Enlarged. No. 62, 

 Whitehorse collection. 



36. — Outline of another specimen, showing spire. Enlarged. No. 63, 

 Whitehorse collection. 



Worthenopsis depressa. Page 164. 



4. — Lateral view of specimen, natural size. 



4a. — Nearly vertical view of the same. No. 45, Whitehorse collection. 



Orthonema? texana. Page 168. 



5. — Squeeze of specimen, showing general form of the shell. No. 1, 

 Dozier collection. 



5a. — Squeeze of a diagonal section of a mold which makes the shell ap- 

 pear too obtuse. No. 2, Dozier collection. 



Murchisonia gouldii. Page 167. 



6. — Lateral view of squeeze, enlarged about two and a half times. No. 

 14, Dozier collection. 



6a. — Enlargement of same, showing surface marks. 

 66. — Another individual. 



Murchisonia collingsworthensis. Page 166. 



7. — A detailed enlargement of the mold from which the squeeze shown 

 in the following figure was taken. 



7a. — View of squeeze, showing form of spire. No. 36, Dozier collection. 



(over) 



