-rnoi-01'A 



Io*< I 



Hall united with it. Tin- latter, if correctly represented by Hall's figures (loc. n'M. 

 is so different that \\f have no hesitation in pronouncing it a distinct species. So 

 far as our experience is concerned, L. pcrangulata is an unusually constant species. 

 Our (inures represent extremes of variation as exhibited in a large number of 

 specimens. 



Formation and ioeaJtfy. Stone* River KT..UP, Watortown, New York; Murfrcexboro, Tennessee; 

 Meroer county, Kentucky; and, somewhat doubtfully, Minneapolis, Minnesota; Black River group, Pan- 

 queue's rapid, Canada. 



k B. O. Ulrlch. (About 100 specimens.) 



IXH'HOSI'IEA ACUMINATA, H. Sp. (OT VAT. of PERANGULATA.) 



I'I.VTK i.xxnr. no. a. 



Hight 10 mm. or less; apical angle about 42. Volutions seven or eight, all 

 contiguous; peripheral carina very prominent, trilineate, the central part of the 

 band sharply angular; lower carina very strong, upper carina wanting; no umbilicus. 



Resembles and perhaps is merely a later variety of L. perangulata Hall, yet 

 readily enough distinguished by its more depressed and more numerous volutions, 

 especially considering that it is a smaller shell. It differs further in being relatively 

 higher, the apical angle being narrower, in the greater prominence of the carinae, 

 and in wanting the umbilicus which is so constantly present in Hall's species. A 

 variety of L. pukhelln is rather abundantly associated with this species at Spring 

 Valley, Minnesota. It may be distinguished at once by its relatively strong upper 

 keel, L. uruminnta being without this keel. 



Formation and locality. Richmond group, Richmond, Indiana, Manchester, Ohio; and near Spring 

 Valley, Minnesota. 



Collection*. Geological and Natural History Survey of Minnesota; E. O. Ulrlch. 



Regittrr. NIL 7383. 



LOPHOSPIRA MKDIALIS, II. Sp. 

 PI.A I II GB. U-. 



High! 1-J to ii' mm.; apical angle 58' to 70, the average about r,:s . Volutions 

 >r seven, all contiguous, somewhat depressed, rounded below; upper slope nearly 

 flat, generally a little concave in the outer half and gently convex toward the suture, 

 occasionally convex enough to form an obscure subsutural angulation: lower carina 

 becoming less dUtinrt with age, never strong, generally quite indi-tinrt; between it 

 and the prominent peripheral carina, which carries the rounded band, the outline is 

 more or less concave; umbilicus small Imt always present Surface markings rather 

 strong, lamellose, strongly curved backward, often gathered into umlulating groups 

 near the umbilicus. 



