238 THE CANADIAN NATURALIST. [Yol. viL 



Genus Gyroceras. 



14. G. NuMA. — The only specimen of this species in the col- 

 lection is a cast of the interior, which is sufficiently perfect to 

 give us the number of the whorls and their form, but does not 

 show the distance of the septa from each other, nor the position 

 of the siphuncle. Shell large, consisting of about three whorls,^ 

 all in contact, except a small portion of the last one at the aper- 

 ture, which is disengnged. The dorso- ventral diameter of the 

 ■whole coil is about 10 inches; of the two first whorls about 3J 

 inches. The transverse diameter of the third whorl at its smaller 

 extremity is 30 lines; dorso-ventral diameter of the same about 

 21 lines. The dorso-ventral diameter of the last whorl at about 

 the point where it becomes separated is -1 inches, but as only a 

 part of the transverse section of tins whorl is seen, and the shell 

 appears to have been compressed laterally, this dimension may 

 be too great. On the ventral side of the last whorl there is a 

 wide, slightly depressed furrow along the median line. This 

 also may be the result of pressure. On a part of the second 

 whorl, six or seven shallow rounded anuulations are indicated, 

 each of them two or three lines wide, and separated by grooves 

 of the same width. A fracture in one place shows that the septa 

 are deeply concave. As the aperture is broken away, it cannot 

 be determined how much of the last whorl is free in the perfect 

 fossil, but judging from appearances I should say not much more 

 than two inches. Corniferous. 



Genus Orthoceras. 



15. 0. Anax. — Shell about 2 feet long and from 3 to 3 J inches 

 in diameter at the aperture. Septa from 6 to 8 in a length of 2 

 inches, where the diameter is 18 lines. Siphuncle nearly central, 

 cylindrical or nearly so, 2 lines in thickness where the diameter 

 of the shell is 16 lines. 



The best specimens in the collection, (those from 1^ to 2 feet 

 in length) show none of the septa except in the 5 or 6 inches of 

 the smaller extremity. One only, shows a single septum which 

 is 5|- lines deep where the diameter is 2^ inches. In the same 

 locality, and in the same state of preservation, were found a 

 number of fragments in which there are 8 or 9 septa in a length 

 of 4 inches, where the diameter is between 2 and 3 inches, I 

 think these all belong to the same species. 



