218 Mr. Salter on Palaozoic Fossils from South Africa. 



Vern., from Spain, which has a roughly tubercular body, a rounded and not highly 

 convex tail, and fan-like side ribs, spinous near their ends; the axis is roughly 

 tubercular, as well as spiny. There is indeed no near resemblance. Both the last 

 species belong to a group of Homalonoti only known in the Lower Devonian 

 rocks. 



The quotation of this species from the Rhenish rocks, by D'Arch. and De Vern. 

 (Trans. Geol. Soc. 2nd Ser. vol. vi. p. 381), is erroneous. H. armatus, Burm., is 

 intended. And there is some mistake in Dr. Sandberger's supposing that the 

 H. Knightii, Sow., had been identified by De Verneuil as from these rocks. The 

 South African specimens are all of one, or at most two, species, neither of them 

 identical with European forms. 



Localities. — In black and grey hard schists, in light-coloured softer micaceous 

 rock, and in dark-coloured nodules, weathering ferruginous, at Gydow Pass and 

 at Leo Hoek ; and in ferruginous nodules and light-coloured argillaceous schists 

 in the Warm Bokkeveld. 



Next to the Homalonotus, the commonest Trilobite is a new species of Phacops, 

 — of the section Cryphaus : — it is the 



Phacops (CryphcBus) Africanus, sp. nov. PI. XXV. figs. 1-9. 

 Calymene Blumenbachii, Murchison, Sil. Syst. p. 654. 



P. 2-5-uncialis, convexus; axi quam lateribus latiore ; capite subtrigono ; oculis parvis ; 

 glabella producta subparallela, sulcis sinuosis, basali profundiore lunato sursum curvato ; 

 Cauda laciniis utriraque quinque robustis, et mucrone centrali brevi lato ; axi obtuso, 6-7-an- 

 nulato. 



The species is in general found of 2-3 inches long, as shown in our figures 2, 

 6, and 9, and at that age may be easily recognized by its convex form, sharp- 

 pointed pleurae, and spinose tail. It is unlike the generally depressed form of the 

 subgenus to which it belongs, and which it connects with the ordinary forms of 

 Phacops {Acaste, Goldf.). The head is nearly a right-angled triangle; the length 

 nearly two-thirds the width. The glabella is blunt-pointed, and is much broader 

 than the sloping cheeks, and divided from them by only shallow parallel furrows. 

 The glabella-furrows are as follows : — the upper one sigmoid, and extending above 

 the eye ; the second short, arched down, and recurved at the tip ; the basal one 

 deeper, longer, and arched upwards ; neck-furrow strong, and much arched 

 upwards in the middle. The neck-segment is convex and has a central spine. 

 Posterior bead-angles short, spinous (fig. 8) ; eye small, lunate, rather prominent, 

 placed near the glabella and more than half-way up the cheek ; (it is not repre- 

 sented far enough forward in fig. 6, h). Surface of head smooth? Facial suture 

 very forward at its outward termination. 



