272 Br. F. R. C. Reed— 



broadly arched below ; posterior margin nearly vertical, slightly 

 concave. Hinge-line straight, equal in length to about two-thirds 

 the height of the shell. Ears well marked off from body. Valves 

 uneqiial in size and unequally convex ; left valve moderately 

 convex, more so than right valve and larger, with higher and more 

 prominent acute beak, having the body sht rply marked off from 

 anterior and posterior ears. Anterior ear small, subtriangular, 

 convex, rounded, depressed, extending only a short distance along 

 anterior edge of shell, with strongly concave inferior margin and 

 byssal gape. Posterior ear large, triangular, flattened, depressed, 

 longer than wide, extending fully three-fourths the length of the 

 body ; posterior edge nearly vertical, broadly excavated, with 

 tip pointed at about 60 degrees. Surface of body of left valve 

 (in cast) marked with a few broad, Ioav, concentric rugae, most 

 conspicuous towards the inferior margin. Right valve showing 

 large posterior muscle-scar situated on edge of body towards base 

 of posterior ear. Ligamental area present on both valves, external, 

 elongated-triangular, longitudinally grooved with fine lines. Hinge- 

 line with traces of coarse crenulations in front of beaks. 



Dimensions (S. 6-i). — Height of shell, c. 65 mm. Length of hinge- 

 line, c. 42 mm. 



Horizon.— Meadioot Beds. 



Locality. — Kilmorie (S. 64). 



Remarks. — There is only one specimen of this shell known to me, 

 and it consists of an internal cast, but it ajjpears to possess such 

 distinctive characters as to merit a specific designation. It can 

 scarcely be regarded as a crushed and elongated example of Actinod. 

 obsoletum, though the surface ornament (so far as it is preserved) 

 rather suggests it. In shape and general characters it much 

 resembles the figures and descriptions of the species described by 

 Hall 1 as Glypodesma erectum (Conr.) from the Hamilton group of 

 New York, and the briefly described Actinodesma Annae Freeh ^ 

 from the Cobienzian, which would have been placed in Glyptodesma 

 if Freeh had admitted its generic or subgeneric separation from 

 Actinodesma ; but our shell is less oblique than A. Annae and has 

 a less pointed posterior ear. The previously mentioned A. erectum 

 Hall, var. nov. eifeliensis Drevermann ^ from the Lower Cobienzian 

 of Oberstadtfeld seems to be almost identical with our new species, 

 but it is broader and shorter. Kegel * is inclined to unite A. Annae 

 with A. obsoletum, thus adopting Drevermann's opinion. But it 

 seems advisable to keep our shell separate from all these species. 



Kochia cajndiformis (Koch). 

 This species, which is a characteristic one in the Lower Devonian 

 of the Continent,^ is subject to some variation in shape, and the one 



1 HalJ, Palceont. New York, vol. v, pt. i, 1884, p. 153, pi. xi, figs. 1-10. 



2 Freeh, op. cit., p. 106, t. vii, fig. 11 ; t. viii, figs. 6-66. 



^ Drevermann, Paloeontogra'pliica, xlix, 1902, p. S3, t. x, fig. 3. 



* Kegel, Abh. k. preuss^. geol. L-andesanst, N.F., Heffc Ixxiv, 1913, p. 55. 



s Freeh, op. cit., p. 74, t. vi, figs. 6-6/; Kegel, op. cit,, p. 55, t. iii, fig. 7. 



