In the twentieth volume of the Bulletin de la Société geologique de France (p.277) a valuable paper with the above title was published. It contains three plates with a number of species, six of which are said to be new. That I cannot agree with all his conclusions Dr. Haug knows well, for, before the work appeared, the author kindly sent me copies of his proof plates for my opinion, and several letters passed between us on the subject; that he cannot agree with all my opinions on matters palæontological the author readily confesses in the present paper. Nevertheless in two cases of importance this paper does bring us more closely into agreement, as I will point out presently.