IOWA ACADEMY OF SCIENCES. 23 



the periphery, flattened or very slijfhtly concave above, prominently rounded be- 

 low, siiture line linear; spiral band very narrow almost linear, very slifflitly im- 

 pressed and occupying a position just above the peripheral angle; on the spire 

 the band is obscured by a single series of conspicuous nodes; aperture sub- 

 quadrate, or subrhombic; umbilical region slightly impressed, but not per- 

 forated; surface glabrate; under a glass exhibiting fine lines of growth; the last 

 whorl with a series of small transverse folds, or wrinkles, toward the tuberculated 

 margin; each fold apparently originating at a node and extending about one-half 

 or two-thirds the distance to the periphery. 



Twenty or more specimens of this beautiful little species have been obtained 

 from the black superimposed shales of coal. No. 8, at the Giant Mine, No. 1. It 

 approaches more closely than any other the form described by Cox as P. depressa 

 and may eventually prove identical with it. P. depressa, however, was preoccupied 

 by Phillips in 18o6; and this name was also used by de Koninck and by Passy. 



SOLENISCUS nUMILIS. 



Shell very small, short, subfusiform, or elongate-subovate; spire prominent, 

 forming one-third or more of the entire length of the shell; volutions about six, 

 increasing moderately in size, slightly convex. Test rather thin. Columellar fold 

 distinctly visible within the aperture, which is subelliptical; callosity clearly 

 defined but not conspicuous; outer lip thin, sharp. Suture well-defined but not 

 deeply impressed. Surface smooth, but under a glass exhibiting lines of growth. 

 Length G mm. ; width 3.5 mm. 



Ibis little species is from the superimposed black shales of coal No. 3, at the 

 Giant mine; and is found associated with the numerous other small gasteropods 

 mentioned in another place. 



A NEW CONOCARDIUM FROM THh] IOWA DEVONIAN. 



BY CHARLES R. KETES. 



CONOCARDIUM ALTUM. 



Shell of medium size, subtrigonal, anterior view broadly cordate. Anterior end 

 truncate, with a forward slope from the umbones to the lower anterior sharply 

 rounded extremity. Dorsal margin behind the beaks slightly curved, with the 

 edges of the valves incurved, while in front of the beaks it is oroduced forward into 

 a more or less prominent alate extension; basal margin crenate within; posterior 

 extremity at tl.3 hinge line decidedly argular. Beaks rather prominent, gibbous, 

 incurved. Hiatus lanceohte; occupying about two-thirds of the lower posterior 

 margin. Surface marked by simple, regular, radiating cost;i', about forty in num- 

 ber, twenty-five of which occupy that poition of the shell behmd the umbonal 

 slope; the umbonal slope is broad, bordered on each side by a prominent costa 



• Described and figured with other forms in the Proceedings Academy Natural Sci- 

 ence of Philadelphia, 1868, pp. 247-248. 



