﻿Vol. 6 I.] SOME OF THE LOXONEMATID.E. 565 



better specimens shoAV further distinctive features, such as to justify 

 their forming a new subgenus, I would suggest the name of 

 Rhabdostropha. Both these species are of Silurian age. 



Several forms possessing- spirally striated whorls have been described 

 among the Loxonematidae, but they all differ from the species 

 under discussion by having the lines of growth much less sigmoidal. 

 Among them may be mentioned the Devonian Locconema reticulatum, 

 Phill., 1 and numerous Triassic shells, some of which have been 

 referred to new genera. One of these new genera, namely, Hetero- 

 cosmia, Koken, 2 differs still further, in having more convex whorls 

 which are not adpressed at the suture. 



Hitherto but two British species of Loxonema have been described 

 of Silurian age, namely, L. simwsum, Sow., and L. elegans, M'Coy. 3 

 The former is a good species ; the only specimen of the latter, 

 however, is too imperfect to make anything of. It is from the 

 Lower Ludlow Beds. 



I desire here to express my gratitude to Prof. T. McKenny 

 Hughes, F.R.S., for the loan of specimens, and to Mr. E. T. Newton, 

 F.B.S., Mr. H. A. Allen, and Mr. B. B. Newton, for their kindness 

 in affording me facilities in studying fossils under their care. My 

 sincere thanks are also due to Mr. C. D. Sherborn and Mr. J". G. 

 Goodchild for assistance in looking up references. 



Family Loxonematid^, Koken. 

 Genus Loxonema, Phill. 

 Loxonema Grindrodii, sp. nov. (PL XXXVII, fig. 1.) 



Diagnosis. — Shell elongated, turriculated, composed of more 

 than four whorls. "Whorls increasing gradually, adpressed at the 

 suture, convex below. Ornamented by fine spiral lines, two 

 of which are sometimes stronger than the others, and give the 

 appearance of a band situated rather below the middle of the whorl. 

 Lines of growth sigmoidal, numerous fine lines being intercalated 

 between stronger ones, and the greatest sinuosity occurring slightly 

 above the middle of the whorl or else being sub-median. Aperture 

 sub-ovoid. 



Remarks and Besemblances. — The best-preserved specimen 

 of this species is in the Museum of Practical Geology, Jermyn Street. 

 There are three examples in Prof. Groom's collection, which possibly 

 belong to it, but the surface of none of them is well preserved, the 

 biggest alone showing some traces of spiral striee and lines of 

 growth. The spire seems more slender; this may, however, be partly 

 accounted for by the manner of preservation, as all are external 



1 ' Pal. Foss. Devon, &c.' 1841, p. 139 & pi. lx, fig. 187*. 



2 Neues Jahrb. vol. ii (1892) p. 30, footnote. 



3 ' Brit. Paleeoz. Foss.' 1852, p. 302 & pi. i K, fig. 34. 



