Yol. 51.] MT7RCHISONIA AND ITS ALLIES. 219 



the description and figure are not sufficiently precise for comparison 

 with other species. 



Parona (Boll. Soc. Greol. Ital. vol. ix. 1890, p. 56) gives three 

 species from Monte Pizzul in Carnia, viz. M. angulata, Phill. & 

 De Kon. ; a new species allied to M. conula, De Kon. ; and an 

 undetermined species allied to M. nana and M. nodosa, De Kon. 



Waagen (Palseont. indica, ser. 13, Salt Range fossils, vol. i. pt. ii. 

 1880, p. 125) records only one species in India, M. conjungens, and 

 it is imperfectly preserved. 



In the Catalogue of Australian Fossils (1878), p. 84, R. Etheridge, 

 Jun., gives five Carboniferous species : M. angulata, Clarke, carinata, 

 Etheridge, ? tricincta, Morris, trifiliata, Dana, and Verneuiliana, De 

 Kon. The first he refers with a query to M. Verneuiliana, De Kon. ; 

 31. carinata is merely a cast ; M. tricincta is small, and the sinual 

 band is not indicated; and ill. trifiliata is short and more like 

 Pleurotomaria. 



There are about twenty-three American species, but two, 

 M. kansasensis, Swallow, and M. perversa, Swallow, are referred 

 to the genus with a query, and many are not figured, so that it 

 is impossible to compare them satisfactorily with species from 

 other countries. Of those which are figured the following species 

 resemble British forms in certain points, but as they are mostly 

 small they cannot be identified from figures with certainty : — 

 M. attenuata, Hall, and vermicula, Kail, bear some similarit} 7 - to 

 ? Orthonema Youngianum, Don. M . Copei, White, resembles M. cle- 

 planata, Don., but is distinguished by its greater size and wider 

 spiral angle. M. nebrascensis, Geinitz, also differs from M. Kirhbyi, 

 Don., in its wider spiral angle, though it resembles it in other 

 respects. M . turritella, Hall, is very like M. quadricarinata, M'Coy, 

 in the form of the spire, in the position of the sinual band, and in 

 the number of keels with which it is ornamented. M. terebriformis, 

 Hall, differs from M. sphcerulata, Don., in possessing a greater spiral 

 angle and in having stronger and less numerous lines below the 

 sinual band. 



In conclusion I must express my gratitude for the facilities 

 afforded me on all sides in the preparation of this paper. Dr. John 

 Young, Mr. James Thomson, Mr. John Smith, and Mr. Joseph 

 Wright have all been extremely kind in lending me specimens ; 

 and those in charge of the different public collections have given 

 me every assistance in their power. 



II. Description oe the Species. 



Mukchisonia, sensu stricto. 



M'urchisonia cincta, sp. nov. (PI. YIII. figs. 1, 2.) 



Shell small, turreted, composed of more than eleven whorls. 

 Apex acute. Nucleus consisting of about two whorls, cylindrical, 

 smooth, apical one convex. Whorls rounded, increasing gradually. 

 A wide space about the middle of each whorl, bounded on each side 



