504 Systematic Paleontology 



beneath the eyes deep, narrow with elevated margin having a vertical, 

 outward slope. Occipital furrow widening from the dorsal furrows out- 

 ward and coming to a rather abrupt termination without meeting the sub- 

 marginal depression of the cheeks or extending on the genal expansion. 

 Eyes large, elevated, the palpebrum higher than the palpebral lobe. 



" The thickened border bears a row of crenulations or crescentic orna- 

 mental processes, which are the most extended at the anterior extremity; 

 here also the anterior three of these processes are somewhat coalesced. 

 From this extremity may be counted, on both sides of the terminal process, 

 from 12 to 15 similar processes, becoming uniformly smaller toward the 

 genal extremities and finally disappearing altogether at or near the lateral 

 termination of the facial suture. In smaller specimens the number of 

 these processes may be considerably less. 



" The surface of the eephalon is ornamented, on the frontal lobe of the 

 glabella, with coarse pustules of varying size ; this lobe also bears the 

 elongate median scar which occurs in many species of the genus. The 

 coalesced second and third lobes are also pustulose, but less strongly. 

 The cheeks directly beneath the eyes bear traces of low ramifying grooves 

 similar to those found in Dal. pleuropiyx of the Helderbergian fauna and 

 Dal. anchiops of the Schoharie grit. Thorax not observed. Pygidium 

 very broadly triangular, the length and width being as 2 to 3. The margin 

 curves slightly outward on each side and terminates behind in a broad, 

 rounded extremity which is slightly elongated, but is not produced into a 

 spine. The axis bears 10 or 11 annulations, and the pleurae 9 or 10. The 

 ribs are undivided by a median groove and are without coarse tubercles." 

 Clarke, 1900. 



A specimen in the collection of Mr. Gordon is referred to this species. 

 The determination has been made from the cast of the eephalon. Crush- 

 ing has somewhat deformed the east, but the features are still fairly 

 definite, except on tlie anterior extremity. The agreement with the de- 

 scription of D. sienimatns is very close, but the following differences are 

 noted : ( 1 ) The occipital furrow is parallel to the posterior margin of 

 the eephalon for less than one-half the distance from the axis as in typical 

 forms. Thence the posterior margin diverges as is not true of typical 



