NATURAL SCIENCES OP PHILADELPHIA. 81 



OKTHONEMA NEWBERRYI, Meek. 



Shell turreted, elongate-conical; volutions eight or nine in 

 adult examples, compressed-convex, with a more outward slope 

 than the general slant of the spire, the most convex part being 

 near the lower side of each, a little above the suture; first one or 

 two very small and depressed, and the next one or two more 

 rapidly increasing in size than those below, thus giving a propor- 

 tionally shorter and more conical appearance to young than adult 

 specimens; suture well defined, in consequence of the prominence 

 of the lower part of each turn just above. Surface ornamented by 

 three very slender, raised revolving lines, one of which is placed 

 a little below the suture, and the other two below the middle of the 

 turns of the spire, and on the middle of the last volution ; of these 

 revolving lines the upper two ai'e broken up into minute, regularly 

 arranged, projecting points, while the other is usuall}^ continuous ; 

 lines of growth minute, sharpl}^ defined, and very regularly and 

 closely arranged, passing vertically and very nearly or quite 

 straight across the volutions. (Aperture unknown.) 



Length, 0.63 inch; breadth, 0.22 inch. 



The general appearance of this ver}' neat little shell, with its 

 three slender revolving lines, two passing around the middle of its 

 body volution, and below the middle of those of the spire, at once 

 recalls to the mind the genus llurchisonia. A moment's exami- 

 nation under a magnifier, however, shows that the sharply defined 

 lines of growth pass straight across the volutions, without making 

 the slightest flexure indicating a sinus in the lip, such as we see 

 in Murchisonia and Pleurotoniaria. 



It is a more slender shell than the t3'pe of the genus, 0. Salteri, 

 M. and W., from the Coal-measures, and has a much deeper suture, 

 and less angular body volution, with other differences in the 

 details of its markings. Although nothing is known of the nature 

 of its aperture and columella, it agrees so exactl}- in all its other 

 generic characters with the genus 07ihonema, that I have no 

 hesitation in referring it to that genus. It is certainlj^ not a 

 Murchisonia, and differs radicallj^ in its ornamentation from 

 Loxonema, and all of the other palaeozoic types to which the more 

 or less similar univalves of the older rocks are usually referred. 



Locality and position. Otsego, Wood County, Ohio, from the 

 Corniferous groups, just above the Glass Sand. Mr. Gilbert. 

 1871.] . 



