576 Professor Emerson on HaWs Geological Collections. 



ings, like many of the fenestrated polycystiua. Other forms imitate the flat circu- 

 lar diatoms, and one cross section recalls a section through a single sphere of 

 Pulvinulina. These forms require to be magnified 30 to 50 diameters. In small 

 pieces of gray argillaceous limestone without special label and not associated 

 with other fossils. 

 Eeceptaculites (new species). 



" The receptaculites is unlike the several species of the Galena limestone of 

 the West or the B. occidentalis of Canada. Mr. Salter speaks of one found in the 

 northern part of the American continent: This may be that species or it may 

 be a new one; which it was we have no means of determining." (E. P. Stevens, 

 Hall's Xar. Aj). 10, p. 594.) We have made inquiry, but can find no trace of this 

 or the other fossils reported upon in the article quoted. 



DiPLOGRAPTUS DENTATUS, Brongn. Sp. 



1838. Fucoides dentatus. Brongn. Hist. Veg. Fos. pi. 6, fig. 9, 12. 

 1865. DipJograptus pristiniformis. Hall, Grap. Quebec Gr. p. 110. 



1875. D\plograptu8 dentatus. Hop. & Lap. Grap. of St. Davids, Q. J. G. S., vol. 31, p. 6.5fi, pi. 

 xxxiv, fig. 5 a-5 A". 



Occurs in pieces 25-35 mm. in length, tapering slowly to a blunt point, 

 Avidth 2.5 to 3 mm. Hydrothecse 22-34 to the inch, average 30. The many forms 

 which I have referred with some doubt to the JD. dentatus in the very wide signifi- 

 cation given to the species by Hopkinson and Lapworth in the memoir cited 

 above, occur i)enetrating the black flinty limestone in various directions, or lying 

 upon the cleavage surfaces of the thin -bedded varieties of the same black rock. 

 In the former case they cannot be exposed for study; in the latter, beautiful casts 

 of the uncompressed polypary are found. Other si^ecimens are variously com- 

 pressed, and the series of figures given by Hoi>kinson & Lapworth would serve 

 perfectly to represent the various forms. In two cases the proximal end is pre- 

 served as in 5 1c [loc. cit.). Other forms have a more scalariform aspect than any 

 there figured. They are all a little more slender than the normal 1). dentatus 

 from New York. The species occurs in comi)any with Triarthrus BecMi, Calymene 

 senaria, Endoceras proteiforme^ &c. 



L realities : In dark -brown silicious limestone weathering dove colored 

 from French Head, Field Bay; and in black fissile silicious limestone at the 

 ni)pcr end of Frobisher Bay and along the north shore of the same. 

 Climacograptus quadrimucronatus, Hall. 



l'^(35. CHmacof/raptu8 qiiadnmncronatm, Hall. Grap. Quebec Grou^), p. 144, pi. xiii, iigs. I-IO. 



Specimens flattened in various ways represent well many of the drawings 

 cited above, and especially a cast in the limestone of an uncompressed specimen is 

 almost \\ fue-HrmUe of the restoration of the species there figured {Joe. cit), excei)t that 



