358 NEW YORK STATE MUSEUM 



same time figured another species which we have found in the fine argil- 

 laceous shales of Parker's ledge. For this I have decided to use Emmons's 

 name s i m p 1 e x, the name L) . secalinus being restricted to the species 

 from the Hudson River group, as described by Professor Hall [ Pal. N. Y. 

 v. i, 1847, p.267]. 



The specimens from Vermont are completely flattened in the shale, 

 and are small as compared with the stipes described by Dr Emmons, as the 

 largest one is scarcely 2 inches in length and the small ones have much the 

 same appearance as the compressed frond of a Phyllograptus, but the simi- 

 larity between the figure given in his American Geology and the central 

 portion of the longer fronds from Vermont is so marked that I think they 

 are identical. Dr Emmons states that the known locality was in the Hoosic 

 slate, but I suspect, from his having worked to the north in Washington 

 county, N. Y. he may have procured the specimen figured from some other 

 place, referring the slate to the same geologic age as that at Hoosic ; this is 

 the more probable, as a similar confusion of localities is to be detected in 

 other parts of his work. The details of the description are drawn appa- 

 rently from the small specimen figured, rather than from the distorted speci- 

 mens usually observed in the Hoosic slate. In several of the Vermont 

 specimens there is a strong, round, central axis, as shown in figure 4, of 

 plate xi, that appears as though a hollow axis had been filled with sediment in 

 a more or less complete manner, thus preserving the form of the axis, while 

 in other specimens it was compressed and all traces of it lost." 



In the course of my work I have subjected all of Emmons's species to 

 as thoroughly critical a study as possible. I endeavored (with Mr Walcott's 

 aid) to ascertain whether Emmons's types are in existence. Through the 

 courtesy of Professor Clarke, of Williams College, Massachusetts (which 

 institution purchased Emmons's collection) I was permitted to examine all 

 the graptolites in the college museum. None of these, however, proved to 

 be Emmons's types. I was thus thrown back upon a careful comparison oi 

 the data furnished by Emmons's text and figures. In the case of the pres- 

 ent species, it is I think possible to say with a considerable degree of cer- 

 tainty ( 1 ) that Emmons's figure is what he stated it to be, viz: Diplo- 

 g r a p t u s secalinus Eaton (F u c o i d e s secalinus Eaton, F . 

 simplex, etc. ) or a (probably preservation facies) variety of D. folia- 

 ceus Murch., and ( 2 ) that Mr Walcott's "Diplograptus ? simplex 

 Emmons" | U. S. Geol. Sur. Bui. 30, [886, p. 92-93, pi. 1 i, fig. 4, 4a] bears 

 no relation to Emmons's species. For Emmons's text [Am. Geol. [856, pt 

 2, p. 204 1 states that: "The upper or young part of the stem is .? g inch 

 wide, and the number of serrations is 24 to an inch. ll narrows towards the 

 base. ... It is confined to the Hoosic roofing slate." 



Turning now to his figure \loc. oil. pi. 1, fig. 1 1 | we find the width '? |a 

 inch and the number of thecae 16 to the inch. In other words, his figure 



