558 MISS JANE DONALD ON THE GENERA [Nov. I906, 



is actually seen on the specimen marked as the type. The surface- 

 characteristics are not seen on any of these specimens. Mrs. Gray, 

 however, possesses a shell which appears identical with this species, 

 and it has the surface fairly well-preserved. A drawing of it is 

 given (PI. XLIII, fig. 5). It is compressed obliquely, so that the 

 whorls are caused to appear more oblique and wider from the point 

 of view taken than they must originally have been ; the sinual band 

 on the body-whorl also is so much broken as to give it an undulating 

 appearance. The tricarinate form of the band is shown on part of 

 the body- whorl and also on the penultimate whorl, and the lines of 

 growth are distinctly discernible on parts of the surface. This 

 species resembles L. perangulata (Hall) 1 in the structure of the band, 

 the character of the lines of growth, and in the tendency of the last 

 whorl to become detached, but it is distinguished by having a 

 greater spiral angle, and no umbilicus. 



Dimensions. — The type (PI. XLIII, fig. 3) consists of three 

 whorls in a length of 8*25 millimetres, the width = 8*25 mm. 

 Another specimen, figured in PI. XLIII, fig. 4, having three whorls, 

 = 8 mm. in length, and about 6 mm. in width ; this is less than the 

 full width would be, were the shell not embedded in the matrix. 

 Mrs. Gray's example is also imperfect, and consists of only three 

 whorls. It is figured (PI. XLIII, fig. 5), and measures 9 millimetres 

 in length and 10 mm. in width. The width here is rendered by 

 pressure greater than it must originally have been. 



Locality. — The type and seven associated specimens are from 

 Tspytty Evan (Denbighshire), while another example in the Sedgwick 

 Museum is from the west of Llanfechan (Montgomeryshire). Two 

 other moulds of shells from this last locality are marked Murchisonia 

 gyrogonia, but the wax-impression of one shows that the lines of 

 growth pass over the keels without deflection for a sinus, therefore 

 it cannot belong to this species ; and the other is too poor for certain 

 identification. There is a small cast in the British Museum (Natural 

 History) from Meifod, Montgomery, marked M. gyrogonia, but it is 

 too badly preserved to make anything of. Mrs. Gray's specimen is 

 from Shallock Mill (Ayrshire). This species has been recorded 

 from other localities in Scotland, but the example referred to here 

 is the only true representative that I have met with. In a previous 

 paper 2 I showed that probably the shells from the Llandeilo of 

 Balclatchie were wholly, or in part, Lophospira variabilis, Don. 



Horizon. — Middle Bala. 



Lophospiea excavata, sp. nov. (PI. XLIII, fig. 6 and text-fig. 1.) 

 Diagnosis. — Shell turreted, composed of more than four whorls. 

 "Whorls increasing at a moderate rate, angular above the middle of 

 the body-whorl and near the middle of the penultimate whorl, 

 deeply concave above the angle, but only slightly concave below. 

 A strong ridge on the angle represents the sinual band, which is 



1 Pal. New York, vol. i (1847) p. 41 & pi. x, fig. 4, non p. 179 & pi. xxxviii, 

 figs. 7a-7b. 



* Quart. Journ. Geol. Soc. vol. lviii (1902) p. 334. 



