62 CANADIAN FOSSILS. 
three other species in the Builth, Llandeilo, and Haverford-west districts. 
(Memoirs of the Geol. Survey, vol. ii, part 1, p. 308.) 
1849. James Nicol enumerated ant Toshiba Graptolithus Griestonensis, 
G. convolutus, G. Ludensis, and G. lacus. (Quarterly Jour. Geol. Soc., 
vol. vi, pp. 63 and 64.) 
1849. J. Hall stated the occurrence of twenty species of graptolites 
in the Lower Silurian rocks; two other species having been found in the 
Clinton formation.* (Proceedings of the Amer. Assoc. for the Advance- 
ment of Science, 1849, p. 351.) 
1850. J. Barrande published a memoir upon the graptolites of Bohemia, 
describing seventeen species of Graptolithus, of which fifteen were new 3 
anew genus, Rastrites, with four species; and the genus etiolites, with 
one species. These are all placed among the Polypi. All of these species, 
except one, are found in the Upper Silurian; four of them occur in the 
colonies of the inferior division, and pass upward to the superior beds; 
while one species is restricted to the lower division. M. Barrande has 
given in this memvir a resumé of the geographical and geological distri- 
bution of the graptolites in the different countries of the globe. 
1850. Prof. McCoy described three species of graptolites, proposing 
the name Diplograpsus for those with a double series of cellules. He 
proposed also the generic name Protovirgularia for a zoophyte which he 
refers to the Gorgoniadx, but which may perhaps belong to the Grap- 
tolitide. (Annals and Magazine of Nat. Hist., vol. vi, 2nd series, 
pp. 270-272.) 
1850. Prof. Harkness described the graptolites found in the black 
shales of Dumfries-shire, recognizing two species of Rastrites and ten 
species of Graptolites. (Quar. Jour. Geol. Soc., vol. vii, pp. 59-65, pl. i.) 
1851. Prof. McCoy published descriptions and figures of graptolites 
from British paleeozoic rocks, adopting the name Diplograpsus for the 
Species with two ranges of cellules. Of fifteen species which he described, 
eleven are identified as those of preceding authors, and three of these 
are recognized as American species. (British Paleozoic Fossils, pp. 
3-9, pl. 1 B.) 
1851. Dr. H. A. Prout described a graptolite, G. Hallianus [= Den- 
drograptus|, from the Potsdam sandstone of the St. Croix River. (Am. 
Journal Science [2], vol. ix, p. 187.) 
1851. Edward Suess published descriptions of Bohemian graptolites, 
reproducing nearly all of those described by Barrande, recognizing several 
other known species, and describing nine new species. He proposed the 
name Petalolithus as a substitute for Diprion, = Diplograptus. (Watur- 
* This number of twenty species included some forms known, but not at that time 
described. 
