SI 



PamilyINAUTILID.^.. 



solenochilus heneyvillense, 11. sp. 



Plate IV, Fig. 4, lateral view; Fig. r>, dorsal rirw and tntnsverse 



fseclloii. the hlack sjw/ maij not he the sipliinicle; 



Fig. a, ventral vieir. 



Species medium size, judging from our incomplete siiecimen. 

 Shell subglobose. Whorls expand laterally much more rapidly than 

 they do dorso-ventrally. Umbilicus small, deep, perforated. Margin 

 of the umbilicus abruptly rounded. Our specimen preserves two 

 volutions, but a complete shell may hav(> tliree or more. The volu- 

 tions are deeply embracing, showing only a small margin in tlie 

 umbilicus. In the early growth of the shell, a transverse section, 

 disregarding the dorsal sinus is subquadrangular, but later, a trans-- 

 verse section becomes subovatc. The lateral surfaces are flattened, 

 and converge toward the ventral side. The ventral side is, in early 

 life, depressed convex, but later, becomes .sharply rounded. Septa 

 only moderately concave, and incrcf^se their distance nphrt with the 

 growth of the shell: but not so rapidly as the shell expands. The 

 sutures have broad ventral and lateral lobes with saddles at the ventro- 

 lateral and dorso-lateral angles. 



A little of the outer shell is preserved on (nir sjiecimen and it is 

 thin, but no surface ornamentation is preserved. The living chamber 

 is unknown. What appears to be the siphnncle is on the ventral 

 side of the center, and our specimen has two chambers broken so as 

 to show smooth septa, at the ventral margin, witliout any evidence of 

 a siphuncle near the ventral margin, where it usually occurs in this 

 genus. 



This species is so different from .S'. collect luii, which it may be said 

 to most resemble, that a comparison is unnecessary to distinguish it. 



Found by G. K. Greene, in the Knobstone Group, near Henryville, 

 Indiana, and now in the collection of Wm. F. E. Gurley, 



