ONONDAGA-SALT SROUP. 347 



713. 24. MURCHISONIA TURRITIFORMIS («. sp.). 



PL. LXXXnr. Fig. 6 a, b. 



Spire elongated, turritiform, composed of numerous flattened volutions ; surface imknown ; 

 columella small. 



This species is readily distinguished by its flattened volutions, which, in the cast, present 

 the marks of a carina near or a little below the centre. One specimen preserves five volu- 

 tions, being imperfect at both extremities : the shell, originally, had probably not less than 

 fifteen volutions. 



Fig. 6 a. The cast of two volutions, near the base of the shell. 

 Fig. 6 b. A cast of five volutions, imperfect at both extremities. 



Position and locality. In the limestone at Gait, Canada West. 



714. 2. SUBULITES VENTRICOSA (n. sp.). 



PL. LXXXIII. Fig. 7 a, b. 



Subulate ; volutions about six, somewhat rapidly increasing, the last one ventricose and 

 equalling in length all the others ; surface unknown. 



The two specimens are both in the condition of casts. In neither of them have I been able 

 to see the aperture ; but the general form of the shell, the mode of convolution, and the form 

 of the last whorl, are so similar to the other species of the genus, that I have thus referred it. 



Fig. 7 (z. A small specimen having much of the last volution broken off, but preserving the spire 



complete. 

 Fig. 7 5. A large individual with the spire incomplete, but preserving the last volution entire. 



Position and locality. In the limestone at Gait, Canada West. 

 715. 5. CYCLONEMA SULCATA. 



Pl. LXXXIV. Fig.la-d. 



Shell ventricose ; volutions about four, subangular, rapidly increasing from the apex, last 

 one ventricose ; surface marked by strong spiral striae, which appear to be arranged in pairs, 

 with a deeper groove between each pair ; aperture rounded, the columellar side nearly straight ; 

 umbilicus small. 



The original of this species is given in fig. 1 c ; and from the close similarity of the other 



specimens, I have been induced to refer them all to one species. Neither of them are perfect ; 



the shell being removed from a great part of the surface, and exfoliated when remaining. The 



umbilicus, which is represented in the woodcut, is seen in a cast, and in the larger specimens it 



[ Paljeontolosy — Vol. II,] 44 



