ART. 21 ORDOVICIAN TEILOBITES ULEICH 53 



this Girvan species of Telephus is neither the same as Barrande's 

 type of the genus nor precisely like any of the other European and 

 American species. I have therefore proposed the new name Tele'phus 

 reedi for it. On comparison with other species it proved to be more 

 nearly related to the Swedish T. wegelini and the Athens T. latus 

 than to T. fractus. Whatever bearing T. reedi may have on the ques- 

 tion of the stratigraphic relations of the Girvan formations to Ap- 

 palachian deposits it seemed — as did also the already mentioned 

 alliances of Balclatchie and Whitehouse species of Ampyx, Remo- 

 pleurides, Dionide, and Onchaspis — to favor correlation of the Bal- 

 clatchie and the Whitehouse with the lower formations of the Blount 

 group. And this conclusion was indicated also by the apparent 

 trend of the evidence of the trilobites — a group of animals that un- 

 deniably is more highly organized than the brachiopods and there- 

 fore expected to offer the more exact correlation data ; a supposition 

 that in this instance failed to be substantiated. However, in justice 

 to the trilobites, it must be admitted that some of the compared 

 species suffered greater disadvantages than the brachiopods in 

 requiring comparison of more or less fragmentary specimens. 



With such contradictory, and in other respects indecisive fossil 

 evidence, the formerly existing extreme difficulty of satisfactorily cor- 

 relating the Ordovician and Silurian formations of Europe with those 

 in America is evident. However, with the developments of the pres- 

 ent year, partly described on preceding pages and supplemented in 

 notes on the British column of the following correlation table (see 

 p. 83), the chances of finally reaching fairly definite results seem 

 much more promising than they were a year or two ago. In fact, 

 though still speaking in somewhat generalized manner, we are now 

 probably warranted in correlating the typical Stinchar limestone ^^ 

 with the Lenoir limestone and the shale with Glenldln graptolites that 

 lies between the Stinchar and the Benan conglomerate with some part 

 of the Athens shale of the Blount group. The succeeding Balclatchie, 

 Ardwell, and Whitehouse groups are less definitely referable to i^osi- 

 tions in the Appalachian sequence. Still, I feel reasonably certain 

 that they are jDOst-Chazyan in age and that the positions to which 

 they are tentatively assigned on the correlation chart are, if not quite 

 correct, at least nearer the truth than were the conclusions respecting 

 their relations to American formations published a few years ago by 

 Raymond -^ in the stratigraphic part of his work on Ordovician 



22 For reasons given on page 84, the designation " typical Stinchar limestone " does 

 not include the doubtless much younger limestone of the Craighead quarry which sup- 

 plied by far the greater part of the fossils mentioned in Reed's lists of Stinchar limestone 

 trilobites and brachiopods besides many other species of classes, especially corals, not 

 monographed by him. 



23 Raymond, P. E., Harvard Coll. Mus. Comp. Zool. Bull., vol. 67, No. 1, pp. 163-180, 

 1925. 



