A Contribution to the Lower Devonian Faunas of Maryland 55 



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 facia! suture. In smaller specimens the number of 

 these processes may be considerably less. 



'' The surface of the cephalon 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. pleuroptyx of the Helderbergian fauna and 

 Dal. ancliiops of the Schoharie grit. Thorax not observed. Pygidmm 

 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 pleurge 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 ceplialon. Crush- 

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

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

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

 noted: (1) The occipital furrow is parallel to the posterior mju-gin of 

 the cephalon 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 

 forms, making thus with the occipital furrow and the lateral margins 

 scalene areas. (2) The genal angle is somewhat more acute. (3) The 

 third side-lobes bear each a small node on the distal ends. 



Occurrence. — Oriskany Formation, Eidgely Member. Cumberland. 



Collection. — Eobert H. Gordon. 



