﻿1I0MAL0N0TUS. 



L05 



4. Dijoleura, Green, 1832. Convex; head wide, semi-oval, or subtriangular, with 

 somewhat pointed front. Glabella narrow, well defined. Eyes rather remote, on gibbons 

 cheeks. Thorax slightly lobed. Tail obtuse, hardly ribbed. (Type, //. Dekayii.) 

 Upper Silurian ; Lower Devonian. 



H. Dekayii, Green. 



H. sparsus, Eaton. 



H. obtusus, Sandberger. 

 ? H. crassicauda, id. 

 ? //. Ahrendi, Roemer. 

 &c. &c. 



5. Burmeisteria, Salter, 1865. Elongate, convex ; head triangular ; eyes approximate 

 on gibbous cheeks. Glabella distinct, lobeless, spinous. Thorax slightly lobed and 

 spinous, as is also the many-ribbed pointed tail. (Type, H. Herschelii) Devonian. 



H. Herschelii, Murch. 

 H. armatus, Burm. 

 H. Greenii, Goldfuss. 

 H. elongatus, Salter. 

 H. Pradoanus, De Vera. 



I have been obliged to include some foreign species, but these are inserted in italics. 

 The genus Homalonotus seems to have been chiefly a northern one in Silurian times, 

 but during the Lower Devonian epoch it was common both north and south of the 

 equator. After this period the whole group was extinct. 



Section — Brongniartia, § 1. 



Homalonotus bisulcatus, Salter. PI. X, fig. 2 — 10. 



Homalonotus bisulcatus, Salter. Appendix to Sedgwick and M'Coy, Synopsis Brit. 



Pal. Foss., pi. 1 g, figs. 24—31, 1851. 



— — M'Coy. Ibid., fasc. 1, p. 168, 1851. 



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



— — lb. Siluria, 2nd ed., p. 74, foss. 12, fig. 2, 1859. 



— — lb. Memoirs Geol. Surv., vol. iii. Appendix, pi. xvi, 



figs. 1—8, 1865. 



H. l-uncialis ovatus Icevis, capile cauddque semiovalibus, rotundatis. Glabella depressa. 

 Gence lata, extus deflexce ; oculi submediani, valde remoti. From una mm gents continua, 

 plano-concava. Tliorax vix lobatus. Cauda semiovata, obtusa, margine angusto recurvo ; 

 axe conico, 11 — 12-annulato, per % longitudinis cauda extenso, et appendice conico ; lateribm 

 S-sulcatis, sulcis duobus anticis valde jor of undis, hand interlineatis. 



Long-ovate, but broader than in many of the genus, with a blunt semi-ovate head 

 and rounded tail, ribbed strongly throughout. Trilobation conspicuous, but not deep. 

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