38 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 76 



spine indicates a spine of larger size than occurs in T . hipunctatus. 

 The anterior spines also are larger, and the rim from which they 

 spring is slightly thicker than in that species. More conspicuous 

 is the greater posterior width of the glabella. Finally, the posterior 

 end of the fixed cheeks is wider, the raised outer edge of the palpe- 

 bral band correspondingly more longitudinal in direction, the antero- 

 lateral angles more bluntly rounded, and the convex area of the cheek 

 more uniformly convex. 



Although none of these structural differences is very conspicuous or 

 impressive it is nevertheless true that hardly a single cranidial fea- 

 ture is precisely alike in the two. Now, since the differences have 

 been determined and pointed out it seems unlikely that others will 

 have as much difficulty in distinguishing properly prepared speci- 

 mens as I had in working them out. Besides, there is always the 

 chance that more striking structural differences may be found in the 

 as yet unknown other parts of the animals. But, after all, the main 

 reason for taking the trouble of determining the differences by which 

 successive stages in the evolution of fossil organisms may be distin- 

 guished and recognized lies in the increasingly great need of 

 unquestionable guide fossils. 



The present species is related also to T. mohergi Hadding, but the 

 differences in this case are too readily determinable by comparison 

 of their respective illustrations in following plates to require further 

 notice here. 



Occurrence. — Ten feet above base of Tellico formation at quarry 

 on south side of Tennessee River, one and one-half miles east- 

 southeast of Southern Railway station in Knoxville, Tenn. A few 

 specimens were found also in the Tellico belt next to the east about 

 6 miles east of Knoxville. At this place the species is associated 

 with T. hircirms and a multitude of Bryozoa in an oolitic and fer- 

 ruginous limestone conglomerate about 300 feet above the base of the 

 formation. 



Holotype.—Q^i. No. 80534, U.S.N.M. 



TELEPHUS HIRCINUS, new species 



Plate 7, Figures 1-9 



Distinguished from other species mainly by its great posterior 

 convexity, stronger neck spine, thicker occipital ring, the larger size 

 and more anterior direction of the anterior spines, and relatively nar- 

 rower anterior rim. The glabella is broadly rounded-conical in out- 

 line, has somewhat flattened slopes with obscurely defined and very 

 shallow depressions representing the second pair of furrows. Sur- 

 face nearly smooth with obscure striations on the post-median 

 (highest) part of the glabella and on the anterior slopes of the fixed 



