COASTS VISITED BY THE ARCTIC EXPEDITION. 577 



Receptaculites occidentalis, Salter. 



Receptaculites occidentalis, Salter, Geol. Survey of Canada (Cana- 

 dian Org. Remains), decade 1, p. 45, t. x. figs. 1-7. 



B. Neptuni?, Hall, Pal. N. Y. vol. i. p. 68, t. 24. fig. 3. 



"We have several fragments of this species, enough, however, to 

 determine them to be portions of B. occidentalism Salter. Its discoidal 

 form, qnincuncially arranged, spiral, yet concentric lines of cells 

 (engine- turned in pattern) upon the upper surface, and their rhom- 

 boidal form on the underside, with round columns having also in- 

 terstitial spaces nearly equal to their diameter, all tend to correlate 

 this with the Canadian species. 



The much more robust or gigantic form which I have named B. 

 arcticus cannot be any expanded portion of the side or side walls of 

 this species ; the tubuli between the endorhin and ectorhin are also 

 different in shape. Salter remarks that " the thickness of the disk 

 near the centre is but little ; but this increases rapidly towards the 

 margin, becoming in some cases half an inch thick at twice the 

 distance from the centre." I refer to this character in case my spe- 

 cies B. arcticus may be a variety of B. occidentalis. 



Loc. Cape Louis Napoleon, lat. 79° 38'. 



Class HYDROZOA. 



Family MONOGRAPTIM]. 

 Genus Monograpttjs, Emmons, 1856. 

 Bastrites, Salter. 



Monographs CONVOLUTUS (His.), var. Coppingeri, Ether. (PI. XXY. 



fig. 1.) 



Prionotus convolutus, Hisinger, Leth. Suec. p. 114, t. 35. f. 7. 



Graptoliilius spiralis, Gein., Leonh. & Bronn's Jahrb. 1842, p. 700, 

 t. x. p. 20-29. 



Oraptolithus convolutus, Carr. Geol. Mag. vol. v. p. 127, t. 5. f. 1. 



Two worn fragments of this subclass and family have been brought 

 home, both unfortunately from the drift of Polaris Bay. Great in- 

 terest is attached to them on account of the age of the Tocks they 

 probably illustrate and characterize. It is the first instance of any 

 Graptolitic form occurring witbin the polar area ; and only one spe- 

 cies of Monograptus (Bastrites), and this from rocks of Caradoc age, 

 seems to be known in America. These fragments appear to be 

 portions of a large Graptolithus or Bastrites, evidently from fissile 

 shales or thin calcareous bands in some argillo-calcareous rocks. 



Although Mr. Carruthers has figured this species in the Geol. 

 Mag. vol. v. t. 5. f. 1, yet I venture to do so again, on account 

 of its occurrence in the Polar collection. Owing to the state d! 

 preservation the two spinous processes from the sides of the cell and 



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