11 



Some of the specimens are proportionally more elongated than others. 

 The front margin appears to be always broadly rounded, and the greatest 

 width at about one-fourth the length from the front margin. 



Length from 4 to 6 lines ; width either equal to or a little less than 

 the length. 



This species resembles 0. varians of the Chazy, but is more numerously 

 ribbed. 



Locality and Formation. 1J mile east of Swanton, Vermont, in the 

 Potsdam group. 



Collectors. Rev. J. B. Perry, and Dr. G. M. Hall. 



OTHER SPECIES OF BRACJIIOPODA. 



In addition to the above there are in the sandstone of Vermont, 1 mile 

 south of the Province line, two other species, one of which appears to be 

 an Orthisina, about the same size and shape as 0. festinata, but more 

 finely ribbed, and an Orthis, somewhat like 0. perveta of the Chazy. 



At Anse au LoTip there are also two species of Orthis, and apparently 

 one Orthisina, all different from the Vermont species. 



CRUSTACEA. 



OLENELLUS THOMPSON!. (Hall.) 



OLENUS THOMPSONI, (Hall) 12th Reg. Rep. N. Y., p. 59. 1859. 

 BARRANDIA THOMPSONI, (Hall) 13th Reg. Rep. N. Y., p. 116. 1861. 

 PARADOXIDES THOMPSONI, (Emmons) Man. of Geol. p. 280. 1860. 



PARADOXIDES THOMPSONI, (Barrande) Bui. Geo. Soc. France. 2d series, vol. 18, 

 p. 276. 1861. 



A well preserved head of this species was collected in the limestone at 

 Anse au Loup. 



OLENELLUS VERMONTANA. (Hall.) 



(The references for this species are the same as P. Thompsoni.) 



Several very good specimens of the glabella and head were collected 

 in the limestone of Anse au Loup. It seems to be more abundant there 

 than P. Thompsoni. 



CONOCEPHALITES MISER. 

 Fig. 14. 



Description. Glabella elongate, conical, very convex, most elevated 

 at about the mid-length, slightly narrowed at the neck segment, widest in 



