190 Bibliographical Notices. 
EXPLANATION OF PLATE VI. 
Fig. 1. Tristychius fimbriatus, Stock, nat. size. 
Fig. 1a. The same, restored. 
Figs. 2 & 2a. Styracodus acutus, Giebel (= Tristychius P). 
Figs. 3 & 3a. Referred by Giebel to Hybodus (= Pleuracanthus ?). 
Figs. 4 & 4a. Chilodus gracilis, Giebel (= Diplodus ?). 
Figs. 5 & 5a, Hybodus vicinalis, Giebel (= Tristychius ?). 
Figs.6 & 6a. Hybodus carbonarius, Giebel (= Tristychius ?). 
Figs. 7 & 7 a. Tristychius arcuatus, Ag., nat. size, and point enlarged. 
Fig. 8. Tristychius arcuatus, Ag., nat. size. s, fragment of pectoral 
spine; 7, displaced neural spines; 7, doubtful traces of the rays 
of the pectoral fin. 
Fig. 9. Tooth of Tristychius arcuatus, Ag., nat. size. 
Fig. 10. The same, showing base, nat. size. 
Fig. 11. The same, nat. size. 
Fig. 12. Four teeth of Tristychius arcuatus, Ag., im natural position, nat. 
size. 
Figs. 13 & 13a. Spine of Tristychius arcuatus, Ag.: fig. 13 nat. size; fig. 
15a enlarged, to show the nature of the sculpture. 
Figs. 14 & 14a. Dermal tubercle of Hybodus carbonarius, Giebel ; fig. 14 
enlarged. 
Fig. 15. Dermal tubercle of Tristychius arcuatus, Ag., much enlarged. 
Fug. 15a, The same, one of the prongs much enlarged, to show the 
sculpture. 
Fig. 16. Dermal tubercle of Ctenacanthus hybodoides, Ag., slightly en- 
larged. 
Fig. 17. Dermal tubercle of Gyracanthus tuberculatus, Ag., much enlarged. 
Fig. 17 a, The same, one of the prongs much enlarged to show the dia- 
gonal sculpture. 
Fig. 18. Tooth of Tristychius arcuatus, Ag., enlarged, showing the slight 
elevation of the lateral cusps. 
Fig. 19. Styracodus acutus, Giebel. 
BIBLIOGRAPHICAL NOTICES. 
Atlas de la description physique de la République Argentine conte- 
nant des vues pittoresques et des figures d’ Histoire naturelle com- 
posées par le Dr. H. Burmeisrer, Directeur du Musée public de 
Buenos Aires, &c. Le texte traduit en francais avec le concours 
de E. Darreaux. Deuxicme section. Mammiferes. Premiere 
Livraison. Die Bartenwale der argentinischen Kusten. 
’ Erléuterungen zur Fauna Argentina, enthaltend ausfuhrliche Dar- 
stellungen neuer oder ungeniigend bekannter Stiugethiere von H. — 
Burmerster, &c. Erste Lieferung. Die Bartenwale der argenti-— 
nischen Kiisten. Buenos Aires: Paul-Emile Coni. Paris: F. 
Savy. Halle: Ed. Anton. 1881. i 
Dr. Burmutster’s ‘ Natural History of the Argentine Republic’ was — 
interrupted on the completion of the first section by a change of 
government. ‘The author, however, had from time to time trans-_ 
