Eastman. — Dinichthya. 



PLATE 2. 



Fig. 1. Dinichthysterrelli^evfh. X ?• Cleveland Shale; Lindale, Ohio. M. C. Z., 

 Cat. No. 1379. Fragment showing internal surface of antero- and 

 postero-dorso-lateral plates preserved in natural association with each 

 other. Their union by pegs and sockets, the sinuous lateral boundary 

 of the posterior plate, and the base of articulating condyle of the 

 antero-dorso-lateral, are noteworthy features. 



Fig. 2. Postero-ventro-median plate of an indetermined Dinichthyid species, from 

 the Cleveland Shale of Lorain Count}', Ohio. X ^ (approximately). 

 M. C. Z., Cat. No. 1300. The external surface, shown here, bears im- 

 pressions of overlapping plates, and is notched in front for reception 

 of tiie antero-ventro-median. 



Fig. 3. Dinichtkys bohemicus (Barr.). X |. Middle Devonian (Etage Gg^); 

 Svagerka, Bohemia. M. C. Z., Cat. No. 1377. Tuberculated dorso- 

 median plate. The posterior portion of the specimen, which was 

 fractured obliquely downward, has been ground smooth and polished, 

 so as to show the inferior carina in section. 



Fig. 4. Dinichthys pelmensis sp. nov. X \- Middle Devonian ; Pelm, Eifel Dis- 

 trict. M. C. Z., Cat. No. 1375. Dorso-median plate with perfectly 

 preserved carinal process, and faint indications of sensory canals. 



Fig. 5. Dinichthys terrelli Newb. X 5- Cleveland Shale ; Lorain County, Ohio. 

 M. C. Z., Cat. No. 1301. Antero-ventro-median plate, seen from the 

 external surface. Thickness at posterior tip less than 2 mm. ; the 

 plate has every indication of being entire, or very nearly so. 



Fig. 6. Same specimen as shown in Fig. 5, viewed from the internal or visceral 

 side. Tiie thickened T-shaped ridge seen on this surface is very 

 characteristic. 



