22-k 



rroceedinys of the Royal Physical JSocidy. 



(11.) Tkautschold, H. — " Ueber Coccosteus meyalopteryx, 

 Trd., Coccosteus obtusus und Chelioiohorus Verneuili, 

 Ag.," Zeitsclir. der deidsch. geol. Gesellsch. 1889, pp. 

 35-48. 



(12.) Tkaquair, It. H.— "IsTotes on the Nomenclature of the 

 Pishes of the Old Eed Sandstone of Great Britain,"- 

 Geol. May. (3), vol. v., 1888, pp. 507-617. 



(13.) Traquair, K. H. — " Homosteus, Asniuss, compared with 

 Coccosteus, Agassiz, Froc. Hoy. Fhys. Soc, vol. x., pp. 

 47-57. 



(14.) ZiTTEL, K. A. VON. — "Handbuch der I'alaeontologie," 

 i. Abtheilung, iii. Band, 1 Lieferung. 



Explanation^ of Plate. 



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



in. 0. Median occipital. 



c. 0. External occipital, 



VI. Marginal. 



c. Central. 



2)t. 0. Post- orbital. 



2). 0. Pre-orhital. 



2)1. c. Posterior ethmoidal. 



a. c. Anterior ethmoidal. 



}). inx. Premaxillary. 



n. Nasal opening. 



inx. Maxillary. 



j. Jugal. 



o. Orbit. 



ni. d. Median dorsal. 



a. d. I. Anterior dorso-lateral. 



2). d. I. Posterior dorso-lateral. 



a. I. Antero-lateral. 



j). I. Postero-lateral. 



i. I, Interlateral. 



a. in. V. Anterior median ventral. 



m. V. Median ventral. 



a. V. I. Anterior ventro-lateral. 



2). V. I. Posterior ventro-lateral. 



X. Peculiar internal bones. 



y. Posterior ventral plate. 



inn. Mandible. 



Fig. 1. Pestored outline of the skeleton of Coccosteus deci2)icns, 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. 



