K 



i'of. F. M'Cov on some new Lower Palaozoic Mollusca. 191 



I 



vex below the middle ; band broadj depressed, bounded by two 



delicate prominent keels, the upper edge being a little below 



the middle of the whorl ; a space equal to the band in width 



is visible below it on the turns of the spire ; base flattened, 



gently convex, slightly umbilicate ; surface with close, sharp, 



irregular, interrupted striae, slightly arched backwards from 



the spire to the suture, and in the opposite direction beneath 



it ; the oblique strise faintly crenulated by very minute spiral 



itriaj, the band with coarse, irregular, backward ai'ched lines 



nly. Length 6 lines, proportional width j^/^, length of body- 



I'horl-^-Q- 



This bears some slight resemblance to the Turbo carinatus 

 (Sow.) of the Upper Ludlow, but is generically distinct by its 

 strise arched backwards to the band ; its spire is also shorter, and 

 there are no spiral ridges on the base. 



In the Upper Ludlow rock of Brigsteer, Kendal, Westmore- 

 land. 



[Col. University of Cambridge.) 



Murchisonia cancellatula (M'Coy). 



Desc. Conic ; apical angle about 50° ; spire of four whorls, ob- 

 tusely angulated a little below the middle ; the part above the 

 keel oblique, slightly convex near the sutures, slightly concave 

 near the keel ; portions below the keel convex ; body whorl of 

 moderate size ; base apparently imperforate (but imperfectly 

 seen) ; mouth obscurely rhomboidal, a little wider than high. 

 Length 1 inch 2 lines, proportional width -j-^-^^, height of body- 

 whorl -^jf-j^ ; entire surface above and below the keel reticulated 

 by nearly equal spiral and backward curved, oblique, trans- 

 verse sulci, eight or nine in one line. 



Mr. Salter, on a casual examination of some of our specimens 

 of this species, supposed them to belong to his Murchisonia sca- 

 laris (Geol. Journ. vol. v. t. 1, fig. 2), which he there says is a 

 common Bala species, recognized by its elongate shape, &c., and 

 imperfect specimens of the exterior of which he says show the 

 fine strise curving back to the keel ; but as the carinated species 

 I have seen from Bala are quite diff"erent from the present, and 

 agree with the above figure in the elongate form, so difi"erent 

 from the present shell, which also has strong spiral strise, not 

 said to exist in the M. scalaris, nor in the Bala forms which I 

 have seen, I conceive this to be a perfectly distinct species. 



In the Upper Bala rock of Allt yr Anker, Meifod, Mont- 

 gomeryshire ; abundant in the sandstone of Mullock quarry, 

 Dalquorhan, near Girvan, Ayrshire. 



{Col. University of Cambridge.) 



