304 THE CANADIAN NATURALIST. [Vol. ix. 



With reference to the foregoing list, the following points are 

 ■worthy of note : 



1st. That all the species obtained (36 in number), with two 

 or three exceptions are described in Hall's Palaeontology of New 

 York, showing the close relationship between the rocks of the 

 Island and the typical strata in New York. 



2nd. In the collection are several specimens of >S'^n'c^'?aricZmia 

 Gasi^ensis, Strophoinena punctulifera and Spirifer cyclopterus 

 shells characteristic of the Helderberg strata of Gaspe ; so that 

 by its organic remains the limestone of St. Helen's Island is 

 related to the Gaspe beds, as well as to the New York strata. 



3rd. Pentamerus pseudo-galeafus, Atrypa reticularis^ Spirifer 

 concinnus are found in abundance on the Island, the latter to 

 such an extent that it may be regarded as the shell most highly 

 characteristic of this deposit. 



4th. In the limestone of the Island are found two species 

 which are regarded as belonging to the Oriskany sandstone, 

 Orthis hipparionyx and Spirifer allied to S. arenosus. 



Hall, in the Palaeontology of New York, says the transition 

 from the Oriskany to the Helderberg is very abrupt, and few 

 species pass from the latter to the former. It is therefore 

 remarkable that in a deposit so limited in extent we should find 

 two species which pass from the Helderberg to the Oriskany. 



5th. The tentaculites mentioned as T. Helena is a new species, 

 somewhat resemblino; T. annulatus of the Lower Silurian fio-ured 

 by Murchison in his '' Siluria." The characters are as follows : 



Tube strong, somewhat rapidly enlarging from apex. Varies 

 in length from j^ to |- of an inch. Annulatcd by sharp elevated 

 rings, extending to the apex, eight to nine in the eighth of an 

 inch. Spaces between the striae from two to three times the 

 width of the striae. These spaces are marked by numerous fine 

 vertical markings. This is distinct from any other, so far as I 

 know, by its sharp annuli with vertical markings on the inter- 

 mediate spaces. 



