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The characteristics have already been given in the generic de- 

 scriptions and the presence of the contact furrow in the neanic 

 stage noticed. It only remains to call attention to the fact that 

 this and the dorsal lobes of the sutures are generated together as the 

 whorls come in contact. 



Pycnoceras calciferiforme, n. s. 



Loc, Port au Choix and Schooner Island, Newfoundland and 

 Phillipsburg, Canada. 



This species is sufficiently abundant at Port au Choix, and seems 

 at first identical with calciferus of Port au Choix, but the latter 

 is probably a species of Tarphyceras, having the small siphuncle of 

 that group. 



The shell reaches a considerable size, 128 mm. in the entire 

 diameter. This specimen has a living chamber somewhat over one- 

 half of a volution in length, and a similar living chamber occurs in 

 a younger specimen longer than in Eurystomites. 



The whorl in section is an oval with evenly rounded sides, no 

 umbilical shoulders, and the abdomen broader than the dorsum, but 

 in the neanic stage, and perhaps in the early part of the ephebic 

 stage, the sides are evenly rounded and very gibbous, and the venter 

 may be narrower than the dorsum, measuring through the thickest 

 inner part of the whorl ventrad of the impressed zone. 



The siphuncle is very large, measuring just before entering the 

 living chamber about 7 mm., and is propioventran in position, but 

 less than its own diameter distant from the venter. It has a sub- 

 ventran position in the ananeanic substage, the earliest age observed. 

 Billings described the siphuncle in Tarphyceras calcifems as small 

 at the diameter for the whole shell of three inches, and the septa as 

 numbering about twelve to the inch along the venter at the diame- 

 ter of three inches. At this diameter in calciferiforme the septa 

 are six or eight to the inch, and the siphuncle is about 5 mm. in 

 diameter. 



The contact furrow is very slight at all stages. The septa are 

 deeply concave, approximating to those of Eurystomites gibbosus, 

 but owing to the slight amount of involution the dorsal lobes are shal- 

 low ; thus showing the dependence of this character upon the amount 

 of involution, as well as the concavity of the septa. There are 

 broad ventral saddles with almost straight suture or slight lobes, 

 broad lateral lobes trending forwards to narrow saddles at the lines 

 of involution. 



