WHiTEAVEsJ DEVONIAN FOSSILS OF MANITOBA, ETC. 315 



plate, and the former are narrowly umbilioated. In testiferous specimens 

 the umbilicus is completely closed by an internal thickening of the shell 

 on that side, the tilling of the umbilical cavity Ijeing usually the only part 

 of the test left remaining on internal casts. 



The species appear to range throughout the whole thickness (if the 

 Devonian rocks in this district, but to be more abundant above the 

 Stringocephalus zone than in or below it. It appears to be the Canadian 

 representative of the Rajjliintoma Bronni (Goldfuss, sp.) of the Middle 

 Devonian of Germany and Russia, but differs from that species in its 

 imperforate base, and in the absence of two distant spiral keels or ridges 

 on the apical side of the outer volution. 



(S.) MuRciiisoNiA Archiacana. (Nom. Nov.) 



Plates 41, fig. 7, and 45, tig. 3. 



it'urchixoilia aiiijulata, var. A, d'Archiac and de Verneiiil. 1842. Trans. Geol. Soc. 

 Lond. , Ser. 2, vol. VI, p. 356, pi. x.x.xii, fig. 7 ; but not J/. 

 angiilata, Phillips, 1836. 



A few specimens of a species of Jfurchisonia, which appears to the 

 writer to be identical with J/, angulata, var. A, of MM. cIArchiac and de 

 Verneuil, were collected by Messrs. Tyrrell and Dowhng in 1889 at 

 Weston Point and at five different localities in or around Dawson Bay, 

 Lake Winnipegosis. Most of the specimens are well preserved moulds of 

 the exterior of the shell, in dolomite, and the figure on Plate xli is taken 

 from a gutta percha impression of one of the most perfect of tliese moulds, 

 in which, however, only a very small portion, if any, of the body volution 

 is preserved. The original of this figure has nine angular volutions 

 preserved, each encircled with a single (not channeled) spiral keel, which 

 is subcentral on all those of the spire, and there is a " second, less evident 

 keel on the last volution." The other specimen figured, in which the body 

 whorl and two of the preceding volutions are preserved, shows that the maxi- 

 mum breadth of the body whorl at the aperture is as much as an inch and 

 a quarter, that the base is strongly convex and almost or quite imperforate, 

 and that the aperture is somewhat rhomboidal in outline. Only one speci- 

 men with the test preserved has as yet been obtained at any of the locali- 

 ties visited by Messrs. Tyrrell and Dowling . 



In a paper on some Carboniferous species of Murcliisonia* , Miss Jane 

 Donald states that " considerable confusion has arisen with regard to the 

 identification of the Jfurchisonia angulata of Phillips, owing to his having 

 described three distinct species under this name. In 1836, in the 'Geol. 

 Yorks,' vol. II, p. 230, pi. xvi., fig. 16, Phillips figures and describes two 



' Quart. Journ. Geol. Soc, Lend., vol. XLIII (1887), pp. 621-23. 



