272 Dr. F. R. Cowper Reed — The genus Homalcmotus. 



The so-called " young specimens " from "Wales wbich Salter figured 

 in 1865 (pi. X, figs. 7, 8) must certainly be separated from the 

 typical 11. hisulcatus and are the same as Salter figured in 1852^ as 

 his var. ft minor from Maes Meillion. The poor specimen in the 

 Sedgwick Museum from the Arenig beds of Ty Obry, figured^ as 

 If. bisulcatuH with a query, is of very doubtful specific and even 

 generic reference. 



In the head-shield of the typical Shropshire examples of H. bisul- 

 ■catus the facial sutures unite very close to tbe margin, or actually 

 along its edge in a broad fl.attened curve leaving a wide pre-glabellar 

 nrea at least one-third the length of the glabella. There is therefore 

 no distinct, much less large, pre-sutural area, the free-cheeks and the 

 front end of the epistorae apparently forming only a very narrow 

 band on the edge of the head-shield in front. Baile)-^ sliows this 

 band in a figure of a specimen from the Bala beds of the Onny River. 

 But the inferior doublure, the epistome and epistomal sutures have 

 not been observed or described in any specimen, and in the majority 

 of specimens of the head only the middle-shield is preserved. The 

 glabella, which is urceolate, does not show any lobation, and " para- 

 glabellar areas" are absent or practically obsolete, but I have seen 

 faint indications of them in a head-shield (No. 5) from Marshbrook 

 in the Ludlow Museum. 



A species referable to the same group as M. hisulcatus is 

 H. ascriptus, Reed,* from the Dufton Shales of Melmerby, but it is 

 only founded on head-shields somewhat resembling Salter's var. 

 ft ininor of H. hisulcatus to which reference bas above been made. 



The middle-shield doubtfully referred by Salter to //. Edgelli 

 (Salter, op. cit., pi. x, fig. 10, p. 108) and obtained from the Bala 

 beds of Horderly, must also be placed here. 



A new species allied to Z7". Sedgwichi, from the Bala beds of the 

 Vyrnwy Dam, near Rhayader, has been recognized in the Sedgwick 

 Museum, and the description of it under the name S. Tawneyi is now 

 uwaiting publication. 



The second section of Brongniartia has as its type S. rudis, Salter,^ 

 ■which was founded on two extremely imperfect and distorted casts of 

 pygidia from Capel Garmon, Denbighshire, in the Sedgwick Museum. 

 The Welsh specimens in the Jermyn Street Museum, which Salter 

 mentions (op. cit.) as belonging to this species and some of which he 

 fiubsequently figured in his monograph in 1865 (op. cit., pi. x, fig. 12, 

 Nantyr, Llanarmon -fy-; pi. x, figs. 14rt, h, Cader Dinraael -/g-), are 

 likewise very poor ; the second figured one is, however, better than 

 the original types. The strongly and well-defined axis to the thorax, 

 and the shorter pygidium with fewer axial rings and fewer pleural 

 ribs are features separating it from the species S. hisulcatus. But 



^ Ibid., pi. i G, figs. 29, 30. 



2 Salter, Mem. Geol. Surv., vol. iii (2nd ed., 1881), p. 526, pi. 11a, fig. 8. 

 ^ Bailey, Fig. Char. Brit. Foss., i, pi. xiii, fig. 9a, 1875. 

 * Beed, Geol. Mag., Dec. V, Vol. VII, p. 216, PI. XVII, Figs. 4-8, 1910. 

 ^ Appendix to M'Coy's Syn. Pal. Foss. Woodw. Mus., p. v, pi. i E, 

 figs. 20, 20a. 



