lvi DESCRIPTIVE REMARKS, 
Fre. 14.—Fosst, anp keECENT CRUSTACEAN FOR COMPARISON, 
EURYPrERIDA. 
A.—Pterygotus anglicus ( fossil) restored (after 8—l4. Thoracic somites. 
Woodward). 15—19. Abdominal do. 
1. The eyes 20. The Telson or terminal segment, 
2. Chelate antenne. ms 
3. Mandibles (endognaths). B.—Sapphirina ovato-lanceolata (recent) 
4. First maxillee do. Atlantic. 
5. Second do. : 
6. Maxillipeds (ectognaths). 5. Head shield. t 
7. Head shield bearing the ocelli (0) 6—9. Thoracic somites. 
and large compound eyes (? 7). 10—14. Abdominal do. 
Some of these Crustaceans, particularly the species we have selected 
for illustration, Pterygotus anglicus, or ‘‘ Seraphim,” as certain por- 
tions of it are termed by the quarrymen, must have been of great size ; 
it is estimated, from some of its remains, that it attained a length of 
fully five feet, and was more than a foot in breadth. There are sixteen 
species recorded, twelve of them in British strata, their Geological 
