﻿HOMALONOTUS. 



109 



Section — Brongniartia, § 2. 

 Homalonotus rudis, Salter. PI. X, figs. 12 — 14. 



Homalonotus rudis, Salter. In Appendix to Sedgwick's and M'Coy's Synopsis. 

 Foss. Woodw. Mus. pi. 1 e, fig. 20, 18.51. 



— — JSrCoy. Ibid., fasc. 1, p. 168, 1851. 



— — Salter. Morris' Catal., 2nd ed., p. 109, 1854. 



— - „ Siluria, 2nd ed., p. 539, 1859. 



— — „ Mem. Geol. Surv., vol. iii, plate xvi, figs. 9 — 11, 1865. 



II. maximus, pedalis et ultra, valde frilobus, costatus et corrugatus. Glabella convexa 

 bene disiincta. Oculi antici. Thorax axe lato convexo, pleuris usque ad fulcrum planis, 

 dein deflexis. Cauda semicircularis et latior, axe convexo conico appendiculalo, 7 — 8- 

 sulcato, vix § cauda efficiente, convexo noduloso ; lateribus costis 6 — 7 duplicatis, hand 

 marginem Icevem attingentibus. 



A still larger and coarser species, in all respects, than the last. Our largest specimen 

 must have been a foot long when perfect. The several specimens now collected together 

 show that the lower furrows of the tail are all nearly equal in strength to the upper two, 

 contrary to what is known in H. bisulcatus. Moreover, H. rudis is trilobate, while the 

 other follows the usual form of the genus. 



We have but one specimen of the head, and that, belonging to the specimen fig. 14, 

 is so crushed that it is not worth while to figure it. But it shows that the glabella is 

 convex, and well distinguished from the cheeks, which bear a small eye rather forward ; 

 the neck-furrow is distinct. 



The body has a narrow axis for the genus, and the axal furrows lie some distance 

 within the fulcrum. The axis is convex, as in ordinary genera, and the axal furrows deep. 

 The posterior half of each segment is convex, the anterior, separated by the groove, is 

 flattened. The pleurae are flat as far as the fulcrum, which is placed about one fourth out 

 (as seen in fig. 14 a), and has the usual angular character • the pleural groove is deepest 

 beneath this point. In all these respects H. rudis resembles a Calgmene, and differs from 

 the ordinary forms of the genus. 



The tail is semi-oval, the front much arched ; the axis prominent, conical, and well 

 raised above the sides, which slope gently down, and have seven nearly straight furrows, 

 of which the two front ones are the strongest. The axis has seven or eight rings, faintly 

 nodular on their sides and central part. It extends three fourths the length of the tail, 

 exclusive of its pointed appendix. The side-ribs, six or seven in number, are, at least in the 

 front ones, faintly interlined. 



If fig. 13 be of the same species, of which there is some little doubt, the whole upper 

 surface is finely tubercular. Fig. 12 shows the great size attained by this fossil. 



