222 JIISS J. DONALD ON THE GENUS [May 1 895, 



The band is somewhat higher above the suture than in the type, 

 three keels being frequently visible below it on the upper whorls. 

 Length of specimen figured (PL VIII. fig. 3) 25 millim., width 

 15| millim. 



An external cast in the Oxford Museum, from Osgathorpe, most 

 nearly resembles these Irish specimens, as the angle is situated 

 higher up the whorl. Only five whorls are preserved; length 17 

 millim., width 8 millim. (PL VIII. fig. 7.) 



Formation. Carboniferous Limestone (d 2 ). 



Mdkchisonia eusieoemis, Phill. (PL VIII. figs. 9, 11, 12.) 



Pleurotomaria fusiformis, J. Phillips, 1836, ' Geol. Yorks.' pt. ii. p. 227, 

 pi. xv. fig. 16 ; T. Brown, 1849, ' Illustr. Fossil Conchology Gr. Brit. & Ire- 

 land,' p. 88, pi. xl. fig. 40. 



MurcMsonia excavata, L. Gr. de Koninck, 1843, ' Precis elem. de G-eol.' par 

 J. J. d'Omalius d'Halloy, p. 516. 



Murchisonia Humboldtiana, L. Gr. de Koninck, 1843, ' Descr. des Anim. Foss. 

 du Terr. Oarb. de la Belgique,' p. 410, pi. xxxviii. fig. 1 ; H. Gr. Bronn, 1848, . 

 Index Palasont. p. 747 ; A. d'Orbigny, 1850, ' Prodr. de Paleont. strat.' vol. i. 

 p. 122 ; J. Morris, 1854, Cat. Brit. Foss. p. 259 ; J. J. Bigsby, 1878, ' Thes. 

 Dev.-Carb.' p. 325 ; L. G. de Koninck, 1883, ' Faune du Calc. Carb. de la 

 Belgique,' vol. viii. pt. iv. p. 14, pi. xxxiii. figs. 47-49 ; B. Etheridge, 1888, 'Foss. 

 Brit. Islands,' vol. i. Palaeozoic, p. 301. 



Murchisonia Josepha, A. Goldfuss, 1844. ' Petr. Germ.' vol. iii. p. 26, pi. clxxii. 

 fig. 7 ; A. d'Orbigny, 1850, ' Prodr. de Paleont. strat.' vol. i. p. 123 ; O. Giebel, 

 1866, ' Eepertor. zu Goldf. Petr. Deutschl.' p. 93 ; J. J. Bigsby, 1878, ' Thes. 

 Dev.-Carb.' p. 325. 



Murchisonia fusiformis, H. G. Bronn, 1848, Index Palseont. p. 747 ; J. 

 Morris, 1854, Cat. Brit. Foss. p. 259 ; J. J. Bigsby, 1878, ' Thes. Dev-Carb.' 

 p. 325; R. Etheridge, 1888, 'Foss. of Brit. Islands,' vol. i. Paleozoic, 

 p. 301. 



Shell conical, composed of ten or eleven whorls. Whorls angu- 

 lar, strongly plicated in adult specimens, less strongly so in young 

 ones, the plications commencing at the suture, running downwards 

 to the sinual band, and continuing below the band to the lower 

 suture. Sinual band situated on the angle rather above the middle 

 of the body-whorl, and about the middle or slightly below on the 

 upper whorls ; bounded by two undulating, moniliform keels, the 

 undulations of which do not exactly coincide ; down the middle of 

 each keel runs a fine groove. There is generally an angularity on 

 the body-whorl at a short distance below the band, which appears 

 just above the suture on the upper whorls. The whole surface is 

 covered by numerous fine spiral lines, only visible on well-preserved 

 specimens. Lines of growth fine, distinct, curving backwards to 

 the band above and forwards below, strongly arched on the band 

 itself. Mouth oblong, probably slightly channelled below. Inner 

 lip simple in young specimens, reflected on the columella in adult 

 individuals. Test of medium thickness. 



Pleurotomaria fusiformis, Phill., appears to me identical with 

 M. Humboldtiana, De Kon. The poor figure and short description 

 in the ' Geology of Yorkshire ' have evidently led to this fact being 

 overlooked ; also the original specimen is small and much worn, thus 



