riw Tnlohitcs of the BokkerehJ Bech. 205 



THACOPS CRIST A-GALLI (H. Woodward). 



Plate XXIV., lig. 5. 



1S73. Encrinurus crhta-qaJU, H. Woodward, Quail. Journ. Geol. 

 Soc, vol. xxix., p. 31, pi. ii., figs. 6, 7. 



In the collection from Gamka Poort there is one specimen which 

 is certainly referable to this species. It is preserved partly as a 

 cast and partly in intaglio. Unfortunately it shows only the thorax 

 and the tail. It exactly resembles the specimen described by Dr. 

 W^oodward (now in the British Museum) except that the tuberculation 

 is much less distinct, the axial spines are shorter, and the tail is not 

 produced into a long mucro but only into a short point. From these 

 characters we may conclude that it is a younger individual. 



The differences between this species and PJiacop^ arhiitciis have 

 already been pointed out. 



Localiti/. — Gamka Poort (^T), with /'. nfrtcioiiis. 



PHACOPS AFEICANUS, Salter (pars). 

 Plate XXIV., figs. 6-8. 



1850. Pliacops {CyiiplueuH) africanu^, Salter (pars), Trans. Geol. 

 Soc, ser. '1, vol. vii., p. 218, pi. xxv., fig. 1, not 

 figs. 2-4, 6-9. 



Head nearly semicircular, rather less than twice as broad as it is 

 long, genal angles produced into short points. Glabella occupying 

 nearly half the width of the head, pentagonal, widening slightly in 

 front and ending forwards in an angle of about 120°, divided from 

 the cheeks by but shallow axial furrows ; the first and second pairs 

 of glabellar furrows are faintly marked, especially on the cast, the 

 first being oblique and the second nearly perpendicular to the axis ; 

 the third pair is deeply impressed and is also at right angles to the 

 axis. The occipital furrow is deep at the sides of the axis but 

 becomes shallower and less definite centrally. The neck segment 

 bears a strong median spine. Eyes large and prominent, placed 

 near the glabella and reaching as far I)ack as the third glabellar 

 furrow ; each bears about 144 lenses. 



Thorax consists of ten (?) segments only. Axis prominent, form- 

 ing rather more than one-third of the total width, narrows rather 



