PLATE XIII. 



Du.MANITES (CORONURA) ASPECTANS. 

 Page 33. 

 1. A fragment of the cephalon, showing' the left cheek, the eye and a portion of the glabella. 

 Corniferous limestone. Columbus, Ohio. 

 Fi°\ 2. The left movable cheek, with the visual surface of the eye attached, showing the great elevation 

 of this organ. This specimen is the original of Conrad's description. 

 Corniferous limestone. Near Schoharie, Schoharie county. 

 l iecimen, showing the eye. 

 Fig. 4. A portion of the visual surface of the last specimen, enlarged to six diameters. 



rniferous limestone. Schoharie, Schoharie county. 

 Fig. ">. The pygidium of a small individual, showing the character of the surface ornamentation. The 

 marginal spines and the posterior portion of the shield have been lost, and are restored in 

 outline. 



.is limestone. Columbus, Ohio. 

 Pig. 6. A small pygidium. showing pathological deformity. 



is limestone. Columbus, Ohio. 

 Pig. 7. A pygidium from which the surface and marginal ornamentation has been worn away. This 

 in. 'ii originally used in the description of Dalmanites Helena, Hall. 

 Corniferous limestone. Columbus, Ohio. 

 Fig. 8. A pygidium of average size retaining the marginal spines. The drawing is made from a gutta- 

 percha impression from a natural mould of the dorsal surface, and the tubercles of the sur- 

 face ate obsolete. 



Corniferous limestone. Columbus, Ohio. 

 9. An entire pygidium, showing the normal length of the marginal spines. The surface ornamenta- 

 solete. 



Corniferous limestone. Lirru Rock, war LeRoy, Genesee county. 

 Fig. Id. A large and somewhat impei-fect pygidium, showing the characteristic ornamentation of the crust. 



Corniferous limestone. Columbus, Ohio. 

 Pig. 11. A large pygidium, retaining portions of the marginal spines, and scattered tubercles over the 

 surface. 



Corniferous limestone. Columbus, Ohio. 

 Pig. 13. A fragment showing the terminal portion of a pygidium which is referred with some hesitation to 

 this speeies. i'lie sirt.'oe ornamentation is similar to that in D. aspectans, and the marginal 

 spines have been broken away, with the exception of the final pair which are unusually large. 

 This form is believed to be identical with Mr. Conrad's Asaphus? denticulatus. 

 ■niferous limestone. Schoharie, Schoharie county. 



Dalmanites (Coronuua) myrmecophorus. 



l'agc 37. 



See Plates 11 a. 14 and 15. 

 12. The pygidium of a small individual, which shows a certain degree of similarity with that of 



/;. aspectans in the so what regular arrangement of the surface tubercles. The specimen 



shows, however, the base of tin- strong terminal axial spine characteristic of D myrmecophorus. 

 Corniferous limestone. /,/,„, Rock, near LeRoy, Genesee county. 



