. Annual report. New York State Museum; Science; Science. GRAPTOLITES OF NEW YORK, PART 2 Nyt Mag. f. 283 Naturvidensk. 1885. cf. Pterograptus dilaceratus Herrmann. 27: 190, fig. 7 S t e p h a n o g r a p t u s surcularis Walcott. Geol. Soc. Am. Bui. 1890. 10: 338 Stephanograptus surcularis Gurley. Jour. Geol. 1896. 4:296 Nemagraptus gracilis var. surcularis Elles & Wood. Monogr. Brit. Grapt. pt 3. 1903. , pi. 19, fig. 2-a-d Hall has figured a series of specimens in the above cited publications [see text fig. 196] as growth stages of N . gracilis, but becoming doubtful [1868, p. 179]
. Annual report. New York State Museum; Science; Science. GRAPTOLITES OF NEW YORK, PART 2 Nyt Mag. f. 283 Naturvidensk. 1885. cf. Pterograptus dilaceratus Herrmann. 27: 190, fig. 7 S t e p h a n o g r a p t u s surcularis Walcott. Geol. Soc. Am. Bui. 1890. 10: 338 Stephanograptus surcularis Gurley. Jour. Geol. 1896. 4:296 Nemagraptus gracilis var. surcularis Elles & Wood. Monogr. Brit. Grapt. pt 3. 1903. , pi. 19, fig. 2-a-d Hall has figured a series of specimens in the above cited publications [see text fig. 196] as growth stages of N . gracilis, but becoming doubtful [1868, p. 179] of their ontogenetic relation to that species, suggested sur- cularis as an appropriate name for them. This species has been recog- nized by Lapworth and listed by Gurley [1896] as a separate species, but in the Monograph of British Graptolitcs reduced to a variety of N . gracilis. It is stated there : " It was regarded by Hall as a young form of N . gracilis, but if so the direction of the stipes must have been modified at a later stage of growth of the species, for no V/~ 197 Fig. 196-97 Nemagraptus gracilis var. surcularis (Hall). Fig. 196 Copies 1 « rcre* fru-m nt-pcpnr of Hall's original figures. Fig. 197 Enlargement (x 5) of the proximal portion of a speci- ldlbc 1U11U piCbCIV- men from Stockport, N. Y. (Original in National Museum) ing the aspect of var. surcularis has as yet been found on either side of the Atlantic, although small forms of the type of N . gracilis are not uncommon. We can only consider that they are the same form if we imagine that in the later stages of growth one branch underwent torsion. There appears to be a certain amount of evidence for this view, but it is too small to justify the inclusion of the two under one ; We have found this type to be quite common in a layer of the Nor- manskill shale at Glenmont. Here it forms extremely intricate masses, which have a certain rigid habitus in common that suggests at once a dif- ferentiati
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