Vol. 62.] OMOSPIRA, LOPHOSPIRA, AND TURRITOMA. 



569 



C. Robusta Section. 

 Lophospira subglobosa, sp. nov. (PL XLIV, fig. 12 & text-fig. 4.) 



Diagnosis. — Shell short, turbinate, composed of several whorls. 

 Whorls increasing somewhat rapidly, slightly convexo-concave 

 above, convex below. Sinual baud situated above the middle of 

 the body-whorl and rather below the middle of the penultimate 

 whorl, almost even with the surface, but slightly margined and 

 having a submedian line. Lines of growth forming strong raised 

 threads, curving back to the band above and passing down nearly 

 vertically below, forming crescents on the band where finer lines 

 are intercalated among the strong ones, indicating a shallow sinus 

 in the outer lip. Surface smooth, with very faint indications of 

 spiral lines. Test thin. Aperture unknown. 



Remarks and Resemblances. — I 

 have only met with three specimens of this 

 species, which are in Mrs. Gray's collection 

 and are all imperfect ; one shows the sur- 

 face-ornamentation very well, and there 

 are traces of it on the others. This 

 species bears the characteristics of the 

 Robusta Section of Ulrich, and is very 

 different from the typical species of Lopho- 

 spira, the whorls being more convex and 

 not having the accessory keels with which 

 members of the genus are generally orna- 

 mented. It resembles Pleurotomaria robusta 

 var. Icevissima, Lindstr., 1 but the whorls 

 are not so convex, the band is not so dis- 

 tinctly margined, and the lines of growth 

 are less oblique. 

 Dimensions. — Portions of two whorls are preserved in two 

 specimens, and only a fragment of one whorl in another. That 

 figured in PL XLIV, fig. 12, measures 25 millimetres in length 

 and 36 mm. in width. 



Locality and Horizon. — Craighead (Ayrshire), in beds of 

 Llandeilo age [Lapworth]. 



Fig. 4. — Lophospira 

 subglobosa, sp. nov., 

 from the Llandeilo 

 of Craighead, mag- 

 nified 2 diameters. 



Ttjrriioma, Ulrich. 



I have already given Dr. Ulrich's diagnosis 2 of this genus, and 

 have provisionally referred to it two species, namely T. (?) -poKta 

 and T. (I) pinguis. I could only place these species here provi- 

 sionally as they do not exactly agree with the diagnosis, nor do 

 they resemble in contour the figure of the type-species, Murchisonia 

 acrea, Billings, which unfortunately is represented very imperfectly. 



1 ' Silurian Gastropoda & Pteropoda of Gotland ' Kongl. Svensk. Vet.-Akad. 

 Handl. ri. s. vol. xix, no. 6 (1884) p. 104 & pi. viii, figs. 8-9. 

 - Quart. Journ. Geol. Soc. vol. lviii (1902) p. 330. 



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