BY F. RATTE, ING. DES ARTS ET MANUF., PARIS. 1069 



(Plate XV. fig. 12.) 



A small pygidium which has left its impression in a hollow, 

 is only 6 mm. broad, corresponding to a little over 10 mm. from 

 front to end, the spines not included. These are 12 in number, 

 four between the principals, and three on each side. They, as well 

 as the pygidium, are covered with numerous irregular tubercles. 

 This and other characters correspond to A . Prevosti, (Barr. pi. 39, 

 and Suppl. pi. 12.) But, having only figures to compare with, I 

 can arrive only at doubtful conclusions. Thus the specimen in 

 question shows that the two thickened parts of the principal spines 

 on the limb of the pygidium are continued into a pad along the 

 extreme border of the pygidium between these spines, and join in 

 the middle the extremity of the axis, which is not the case in 

 Barrande's figure. A. Prevosti is placed by Barrande in his "Etage 

 E, Faune III." 



(Plate XV. figs. 13 & 14.) 



Two heads, one 12 mm. between the ocular lobes, the other a 

 little smaller, and corresponding to individuals about 26^ mm. and 

 24 mm. respectively, are very much alike. One shows the casts of 

 two occipital spines, which in the other are broken, but in the 

 first the anterior part of the head is missing, while in the second 

 this part is terminated by a straight line as in A. mira. 



(II.) SECOND NOTE ON TRIBRAGHIOGRINUS CORRUGATUS, 

 RATTE, AND ON THE PLACE OF THE GENUS AMONG 

 PAL/EOCRINOIDEA. 



Tribrachiocrinus corrugatus, Ratte. 

 (Plate XVI.) 

 Proc. Linn. Soc. N. S. W., Vol. IX. Part 4 ; Wachsmuth and 

 Springer, "Revision of the Paleeocrinoidea," Proc. Acad. Nat. Sc. 

 Philad. 1879 to 1886 (1). 



(1) Revision, Part I, Proc. Acad. Nat. Sc. Phil. 1879, p. 226. 

 ,, Part II ,, ,, „ „ ,, 1881, p. 177. 



Part III „ „ „ „ „ 1885, p. 225. 



Part III (Section 2) ,, „ „ 1886, p. 64. 



