18 



Locality and Formation — Arise au Loup on the north shore of the 

 Straits of Belle Isle, m limestone of the Potsdam group. 

 Collector. — J. Richardson. 



Salterella pulchella. (N. sp.) 



Description. — Elongate, conical, gently curved, six to eight lines in length 

 and from one line to one and a-half in Avidth at the aperture. Surface 

 ornamented with small encircling striae just visible to the naked eye. 



This species is larger than S. ruffosa, always a little curved, not so 

 abundant, and when weathered does not present the sharp imbricating 

 annulations of that species. 



Locality and Formation. — Same as S. rugosa, but apparently not in 

 the same bed, as the two species are not found together in the same frag- 

 ments of rock. 



Salterella obtusa. (N. sp.) 



Description. — Six to eight lines in length ; diameter at aperture about 

 three lines. The transverse section is always sub-triangular, and in some 

 of the specimens one side appears to be flat like a Theca, and I Avould refer 

 it to that genus only that the tube is composed of successive layers. 

 None of the s[)ecimcns are perfect, but the form is sufEcicntly different 

 from that of the other tAvo to indicate a distinct species. 



Locality and Formation. — Same as the preceding, but not associated 

 with S. rugosa, although it occurs in the same fragments of rock with 

 S. pulchella. 



2. — On some new species of Fossils from the Calciferous Chazy, Black 

 Jliver, and Trenton Formations. 



Genus EosPONGiA. (N. gen.) 



AsTYLOSPONGiA (pars). — (Roemer). Die Silurische Fauna des Westlichen Tennessee, 

 p, 7, 1860. 



Generic characters. — Sub-globular, pyi-iform or sub-hemispherical 

 sponges, not free, with an internal arrangement of pores (sometimes reti- 

 culated), radiating irregularly from the central axis ; cup of variable 

 depth. 



Dr. Ferdinand Roemer, in his beautiful work on the Silurian Fauna of 

 Western Tennessee, has described three genera of Silurian sponges, — 

 Astylospongia, Palceomanon, and Astraospongia. The first of these, he 

 says, consists of free sponges ; hence the generic name. We have several 



