GRAPTOLITES OF NEW YORK, PART 2 



223 



uiramosus. The former is a Normanskill shale form that has the 

 slender filiform character in common with this species but lacks the close 

 branching, while M . tenui ramosus is distinctly coarser in its structure. 

 The most striking characters of M. circinalis are to be seen in the 

 extreme fineness and spiral and circinate involution of the branches. The 

 latter seems to indicate a wiry nature which contrasts with their extreme 

 slenderness and is not shown by the more flaccid Thamnograptus 

 c a p i 1 1 a r i s. It is possible that the small, curiously contorted tufts repre- 

 sent only the last, thin, terminal, drifted portions of a larger form ; but 

 however that may be, this form obviously possesses peculiar characters not 

 shown by other species known at present. 



GENERA INCERTAE SEDIS 

 CHAUNOGRAPTUS Hall 



In the 11th Report of the State Geologist of Indiana (for 1881) Hall 



has proposed a subgenus Chaunograptus of Dendrograptus for a curious 



species of minute, glossy, black tubular bodies found mostly attached to 



valves. The species description serves as diagnosis of the genus. The 



differences of this species from others of Dendrograptus are stated in the 



following remarks : 



This species is more lax and diffuse than any form of Dendrograptus 

 known, and therefore has been separated from the typical forms of the 

 genus. It occurs free anions other fossils, or attached to some frag- 

 mentary portion of other bodies. In its habit of growth it is quite distinct 

 from any of the forms heretofore illustrated, and it is probable it belongs to 

 a division of the Hydrozoa which has not been recognized in the Palaeozoic 

 formations. 



Until recently only the single Waldron species was known and this had 

 not been taken notice of by graptolithologists. Dr Clarke has lately dis- 

 covered a specimen of a congeneric form in the Devonic rocks of Dolbel's 

 brook, Grand Greve, Gaspe, which he describes as C. gracilis [1907, 

 p. 291]. It is also attached to a brachiopod valve (Leptostrophia 

 magnif ica) and though a little coarser than the Waldron form, clearly 

 possesses the same structure. A third, new form was collected by the 



