﻿On Conodonts and Fossil Annelid Jaws. 



145 



indicates that they have not been broken from the edges of the carapace of 

 any crustacean." 



They are brittle and dissolve slowly in nitric acid. Mostly of a reddish 

 horn color and translucent. Rarely white, though white is the usual 

 tint of the Ohio Carboniferous specimens, and common in the Russian 

 specimens. The Chazy specimens are of a black, glossy tint. 



Prof. Huxley suggested the possibility that they might be the teeth of 

 "Hag fish." 



Dr. Hinde continues: "That, however, the Conodonts can not be 

 referred to the horny jaws of Annelids may be conclusively shown by the 

 discovery, by the writer, of these Annelidian structures in the same strata 

 with Conodonts, from which the former can readily be distinguished by 

 their chemical composition and their resemblance to the jaws of existing 

 Annelids." Our present knowledge of facts is insufficient to decide the 

 question as to the low type of fish teeth. 



1 Owing to the uncertainty respecting the animals to which the Cono- 

 donts belonged, any arrangement of the teeth themselves must almost 

 entirely rest on an artificial basis, and, consequently, possess little Zoologi- 

 cal value ; detailed descriptions and figures, however, * * are of great 

 importance and service for Paleontological reference." 



Some of the difficulties in attempting to classify these minute fossil 

 objects may be appreciated when it is understood in what an isolated, de- 

 tached condition, from the bodies to which they belonged, they are found. 



Different parts of the compound jaw apparatus scattered over and 

 through the rocky strata, and never discovered in such a position as to 

 establish the fact of their belonging to a single animal. 



Dr. Hinde says in his paper " On ANNELID J A WS from the Cam- 

 bro-Si'urian, Silurian and Devonian Formations in Canada and from the 

 lower Carboniferous in Scotland" {Quart. Jour, of the Geol. Soc. Lond., 

 Vol. XXXV., 1879,) that Dr. Ehlers published an account of fossil errant 

 Annelids in 1867 ; and Prof. G. B. Grinnell, of Yale College, Conn., de- 

 scribed {Am. Jour, of Arts and Sciences, September, 1877,) two specimens 

 of Annelid jaws from the Cincinnati Group (Cincinnati,^.,) which he 

 constituted the types of a new genus, Nereidavus. 



Description of the Jaws. "The Annelid jaws occur as small, dark, 

 shining objects, very varied in form, disposed through the rock, quite de- 

 tached from each other, and from the positions they occupied in the head 

 of the animal." Are of a bright, glossy black tint, but when much 

 weathered the black is changed to a rusty, reddish tint. Composed of 

 chitinous matter, and undergo no change in nitric acid. 



