294 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



Figs. 6-8. — Promo palseaster bellulus, new species (also see plates 16 and 18). 



6. Camera lucida drawing X 4 of an interbrachial area. The adambu- 

 lacrals are in natural position, but the interbrachial axillaries and the 

 inframarginals are somewhat displaced. Taken from the specimen on 

 plate 16, fig. 1. 



7. Camera lucida drawing X 7 of the abactinal area of a ray. The 

 ossicles are all displaced, but originally they were united in a spicular 

 and partially overlapping mesh. 



8. Madreporite X 7. 



Upper Ordovicic (Richmondian). Waynesville, Ohio. 

 Harris collection of the United States National Museum (Cat. No. 

 40879). 



Plate 16. 



Fig. 1. — Promopalseaster bellulus, new species (also see plates 15 and 18). 



Retouched photograph, natural size, of the actinal side. The specimen 

 is in limestone. 



Upper Ordovicic (Richmondian). Wajoiesville, Ohio. 



Harris collection of the United States National Museum (Cat. No. 

 40879). 

 Fig. 2. — Promopalseaster spinulosus (Miller and Dyer) (also see plates 17 and 18). 



Retouched photograph, natural size, of the actinal side of the holotype 

 of Palseaster longibrachiatus Miller. The well-preserved columns are the 

 inframarginals, but in places some of the adambulacrals are also shown. 



Upper Ordovicic (Richmondian). Near Clarksville, Ohio. 



Harris collection of the United States National Museum (Cat. No. 

 40881). 



Plate 17. 



Figs. 1 and 2. — Promopalseaster spinulosus (Miller and Dyer) (also see plates 16 and 

 18). 

 Retouched photographs X 3 of the actinal and abactinal sides of the 

 holotype. 

 Upper Ordovicic (Richmondian). Probably near Waynesville, Ohio. 

 Dyer collection of the Museum of Comparative Zoology, Harvard 

 University (No. 16). 



Plate 18. 



Figs. 1-3. — Promopalseaster spinulosus (Miller and Dyer) (also see plates 16 and 17). 



1. Camera lucida drawing X 2, somewhat restored, of the holotype 

 of Palseaster longibrachiatus Miller. 



2. Camera lucida drawing X 7 of the abactinal area of a ray near its 

 base. Shows the large infra- and supramarginals and ambital pieces. 

 Center of ray has spicular ossicles. 



3. Madreporite X 7. 



Upper Ordovicic (Richmondian). Near Clarksville, Ohio. 

 Harris collection of the United States National Museum (Cat. No. 

 40881). 



