136 On the Structure of Coccosteus decipiens, Agassiz. 



Quart. Journ. Geol. Soc. 1860, vol. xvi. pp. 119-136. Contains 

 also notes on Coccosteus by Hugh Miller. 



(8) Huxley, T. H. — " Preliminary Essay upon the Systematic 

 Arrangement of the Fishes of the Devonian Epoch," Dec. Geol. 

 Survey, x., 1861. 



(9) Trautschold, H. — " Ueber Dendrodus und Coccosteus," Trans. 



Imp. Russ. Min. Soc. xv., 1880. 



(10) Koenen, A. von. — " Beitrag zur Kenntniss der Placodermen des 

 norddeutschen Oberdevons," Abh. der konigl. Gesellsch. der 

 Wissenschaften zu Gottingen, xxx., 1883. 



(11) Trautschold, H. — "Ueber Coccosteus megalopteryv, Trd., Cocco- 

 steus obtusus und Cheliophorus Verneuili, Ag.," Zeitschr. der 

 deutsch. geol. Gesellsch. 1889, pp. 35-48. 



(12) Traquair, R. H. — " Notes on the Nomenclature of the Fishes of 

 the Old Red Sandstone of Great Britain," Geol. Mag. (3) vol. v. 

 1888, pp. 507-517. 



(13) Traquair, R. H. — " Homosteus, Asmuss, compared with Cocco- 

 steus, Agassiz," Geol. Mag. (3) vol. vi. 1889, pp. 1-8. 



(14) Zittel, K. A. von. — < Handbuch der Palaeontologie,' i. Abthei- 

 lung, iii. Band, 1 Liefer ung. 





EXPLANATION OF PLATE X. 



(In all the figures the same letters refer to the same things. ) 



m. o. Median occipital. 



e. o. External occipital. 



m. Marginal. 



c. Central. 



pt.o. Postorbital. 



p.o. Preorbital. 



pt. e. Posterior ethmoidal. 



a. e. Anterior ethmoidal. 



p.mx. Premaxillary. 



n. Nasal opening. 



mx. Maxillary. 



j. Jugal. 



o. Orbit. 



Fig. 



m. d. Median dorsal. 



a. d. I. Anterior dorso-lateral. 



p. d. I. Posterior dorso-lateral. 



a. I. Antero-lateral. 



p. I. Postero-lateral. 



i. I. Interlateral. 



a. m. v. Anterior median ventral. 



m. v. Median ventral. 



a. v. I. Anterior ventro-lateral. 



p. v. I. Posterior ventro-lateral. 



x. Peculiar internal bones. 



y. Posterior ventral plate. 



mn. Mandible. 



1. Restored outline of the skeleton of Coccosteus decipiens, Agassiz. 



The dotted lines indicate the ramifications of the lateral-line 



system ; the thin lines on the body-cuirass here and in fig. 3 



denote the overlapped edges of the plates. 

 Fig. 2. View of the head and dorso-lateral portion of the body-cuirass 



from above. 

 Fig. 3. View of the ventral portion of the body-cuirass from below. The 



thin lines denote the overlapped edges of the plates. 



