ART. 21 ORDOVICIAN TRILOBITES ULRICH . 39 



cheeks. The latter are of moderate size and convexity and rounded 

 in outline. 



T. hircinus is larger than T. hipuncfatus but evidently is allied to 

 it and may indeed, like T. iellicoensis, have been derived from it. 

 However, the characters mentioned will, it is believed, serve satisfac- 

 torily in distinguishing them. None of the other species seem close 

 enough to require detailed comparison. 



Occui^rence. — Rare in a highly fossiliferous ferruginous oolitic and 

 crystalline limestone, about 6 feet thick, intercalated in ordinary cal- 

 careous Tellico sandstone in the middle third of the formation, 6 miles 

 east of Knoxville, Tenn. Also in the basal 10 feet of the Tellico in 

 the band one mile southeast of Knoxville. At both places it is asso- 

 ciated with T. telJicoensis and T. transversiis. 



Cotypes.—Csit. No. 80548, U.S.N.M. 



TELEPHUS BILUNATUS, new species 



Plate 6, Figures 8, 9 



A small species known only from its cranidium. This is relatively 

 longer and rounder than in most others of the genus, has small fixed 

 cheeks with the convex areas of same narrow, carinated, and curved, 

 the glabella strongly convex and, including the neck ring, subovate 

 in outline, with a deep sharply impressed crescentic glabellar dimple 

 in either slope, the neck furrow deep and wide, and the occipital ring 

 but little wider than the furrow with a small posteriorly directed 

 spine and in front of this on the anterior edge of the ring a small 

 conical elevation that may have served for visual purposes. Surface 

 apparently quite smooth. 



In general aspect this small trilobite head resembles the corre- 

 sponding part of T. mysticensis, but it is distinguished at once by 

 the strongly impressed crescentic glabellar dimples. These impres- 

 sions are even more sharply defined than in T. hipunctatus, and their 

 outwardly bowed form gives the head so characteristic an appear- 

 ance as to forbid any thought of its reference to any other of the 

 known species. Hadding's T. viohergi may be as near as any, but 

 in that species the antero-lateral part of the outline of the cranidium 

 is move angular, the glabella more depressed convex, and the 

 crescentic glabellar depressions are convex inwardly instead of out- 

 wardly. 



Occurrence. — A rare fossil in the Whitesburg limestone near 

 Albany, Tennessee. Here it was found associated with many re- 

 mains of heads and other parts of T. hipiinctatMS. 



Holotype.—Q2X. No. 80529, U.S.N.M. 



