and the New Genus Protistograjptus. 59 



curved part. Figures 2e and 2f illustrate a common variation, 

 in which the whole cone is broadly curved. They are elongated 

 and extremely attenuated at the apex. One specimen (fig. 2e) 

 is extended into an apparent stout nema. 



Another variation, nearer the type, is that shown in figure 2g, 

 which illustrates a specimen somewhat broader and not quite 

 straight in the apertural part. The aperture is preserved and 

 is quite different from that of P. minutus. One third of the 

 apertural margin is normal to the concave side of the cone. 

 The remaining portion of the apertural margin rises at an 

 angle of 50°, is somewhat rounded, and forms an obtuse spine 

 or lobe. 



This species is the most abundant in the Yale collection in both 

 A and B beds, although Matthew found it not so abundant as 

 P. minutus. 



References. 



Elles, G. L. 

 1898. The graptolite fauna of the Skiddaw slates. Quart. Jour. Geol. 

 Soc, London, vol. Hv, pp. 463-539, text figs., pi. 27. 

 Elles, G. L., and Wood, E. M. E. 



1901. A monograph of British graptolites. Pt. I. Dichograptidse. 

 Monog. Palseontogr. Soc. vol. lv, pp. 1-54, text figs., pis. 1-4. 



1902. A monograph of British graptolites. Pt. II. Dichograptidee. 

 Ibid., vol. lvi, pp. 55-102, text figs. , pis. 5-13. 



Evans. D. C. 



1906. Ordovician rocks of western Carmarthenshire. Quart. Jour. 

 Geol. Soc, London, vol. lxii, pp. 597-643, text figs., pi. 46. 

 Holm, G. 



1895. On Didymograptus, Tetragraptus, and Phyllograptus. Geol. 

 Mag., Decade iv. vol. ii, pp. 1-20. 

 Matthew, G. F. 



1891. Illustrations of the fauna of the St. John group. No. V. Trans. 



Roy. Soc. Canada, vol. viii, sec. 4, pp. 123-166, pis. 9-16. 

 1892a. Illustrations of the fauna of the St. John group. No. VI. Ibid., 



vol. ix, sec. 4, pp. 33-65, pis. 12. 13. 

 18926. Illustrations of the fauna of the St. John group. No. VII. Ibid., 



vol. x, sec. 4, pp. 85-109, pi. 7. 

 1893. Illustrations of the fauna of the St. John group. No. VIII. 

 Ibid., vol. xi, sec. 4, pp. 85-129, pis. 16, 17. 

 Raymond, P. E. 



1914. The succession of faunas at Levis, P. Q. This Journal (4), 

 vol. xxxviii, pp. 523-530. 

 Ruedemann. R. 



1904. Graptolites of New York. N. Y. State Mus., Mem. 7, Pt. I. 

 Young, G. A. 



1913. St. John and vicinity. 12th Internat. Geol. Cong., Guide Book 

 No. 1, Pt. II, pp. 369-399. 



