214 MISS J. DONALD OK THE GENUS [May 1 895, 



from the Carboniferous rocks of the West of Scotland, though gene- 

 rally in wonderfully good preservation, are usually very minute. 

 Any classification founded on the ornamentation alone, such as that 

 of Lindstrom, cannot be considered of much practical value. He 

 divides his Silurian species into two groups, namely, Simplices and 

 Ornatce, the first consisting of shells with smooth whorls, whose 

 surface possesses no further ornamentation than that given by the 

 sinual band and the lines of growth ; the latter including shells 

 whose surface is more or less richly ornamented. If these divisions 

 were extended, so as to include allied species from other formations, 

 they would certainly not apply, for a smooth variety of a single 

 species would be placed in one group, and an ornamented one in 

 the other. 



The groups suggested by Koken are hardly sufficiently distinctive, 

 and there is no apparent advantage to be gained by abandoning 

 names previously given in favour of his. He divides all the Mur- 

 chisonice into three divisions, calling them after characteristic species 

 ■ — Angulatas, Cingulatce, and Cavake. The first name is certainly not 

 advisable, as so much confusion has arisen about the identification 

 of the type species. 



Enumeration of Carboniferous Species. 



In the most recent list of the Palaeozoic Fossils of the British 

 Islands, namely, that of Mr. Etheridge (1888), fifteen Carboniferous 

 species of Murchisonia are recorded. They are M. angulata, Phill., 

 disjoar, M'Coy, elongata, P 'ortl., fimbricarinata^ Young & Armstrong, 

 fusiformis, Phill., Humboldtiana, De Kon., Larcomi, M'Coy, quadri- 

 carinata, M'Coy, semistriata, Young & Armstrong, spinosa, Phill., 

 striatula, De Kon., sulcata, M'Coy, tceniata, Phill., Urei, Elem., and 

 vittata, Phill. 



In ' Notes on some Carb. Gastr. from Penton and Elsewhere,' 

 Trans. Cumberland and Westmorland Assoc, no. ix. (1883-1884), 

 p. 130, I' showed that Turritella Urei, Elem., belonged to the genus 

 Loxonema, and not to Murchisonia, as there is no sinus in the outer 

 lip or band on the whorls, but the shell is ornamented with longi- 

 tudinal ribs. M. semistriata, Young and Armstrong, is referred 

 to the genus Murchisonia by mistake, for it is a Macrocheili na. 

 M. striatula has been placed by De Koninck in the genus Adisina, 

 as it does not possess the characteristic sinus in the outer lip. 

 M. spinosa is a doubtful Carboniferous species. Sowerby, in his 

 ' Min. Conch.' vol. vi. p. 125, pi. dlxvi. fig. 2, describes and figures a 

 species of Murchisonia as spinosa from Bradley, Devonshire, which 

 is of Devonian age. In the 'Pal. Eoss.' p. 150, Phillips refers to 

 M. spinosa as Carboniferous as well as Devonian, and gives White- 

 well, Derbyshire, as the locality for the former. I have examined 

 numerous collections and made a great many enquiries, but have 

 not met with a single Carboniferous specimen agreeing with this 

 species ; the name can hardly, therefore, be retained in the list of 

 Carboniferous species. 



