Tiic Trilobifcs of the Bokkccdd Beds. 213 



This tail presents some resemblance to that described by Ulrich '■ 

 from the Devonian of Chahuarani in Bolivia under the name of 

 Dalmanites clarkei ; but in Uh-ich's species the grooves on the axis 

 seem to be uniformly distinct throughout, and the posterior ribs of 

 the lateral lobes curve inwards instead of outwards. 



Locality. — Gamka Poort (38). 



TYPHLONISGUS BAINI, Salter. 



Plate XXV., figs. 8, 9. 



1856. Ti/phloiii^fus haiiiii, Salter, Trans. Gcol. Soc, ser. 2, 

 vol. vii., p. '221, pi. XXV., tig. 14. 



The specimens of tliis species show the cluiracters of the head 

 much more perfectly tlnin those which Salter- had before him, Init 

 are mostly smaller. 



Head semicircular, genal angles slightly produced, surface scro- 

 biculate. Glabella trapezoidal, widening rapidly in front, frontal 

 margin rounded ; separated from the cheeks by deep axial furrows. 

 The first glabellar furrow is obliquely inclined forwards and rather 

 shallow, the second and third are nearly at right angles to the axis, 

 and deeply impressed ; all are rather short. The cheeks are much 

 swollen, triangular in shape, with a distinct margin separated by a 

 well-marked marginal groove-; no trace of eyes or of facial suture is 

 visible. Occipital furrow well defined. 



Thorax narrows rapidly posteriorly. Axis narrow and rather 

 prominent. Pleurie straight and horizontal for a distance about 

 equal to the width of the axis, and then bent abruptly backward and 

 somewhat downward ; deeply grooved, the ridge in front of the 

 groove being considerably less prominent than that behind. 



Localities. — Gydo Pass (37) ; Gamka Poort (ll, 16, 63, 71). 



PKOETUS MALACUS, sp. nov. 

 Plate XXV., fig. 10. 



Body ovate. Head parabolic, broadly marginate, genal angles 

 produced into spines. Glabella subquadrate, rounded in front, 

 reaching to the margin, raised above the level of the cheeks but 



* Neues -Jahrb. Beil.-Baiid viii., 1893, p. ly. 



