PLATE XXXVIITI. 
Fie. PAGE. 
1. Macropoma mantelli, Agassiz; left pectoral arch, branchial arches, and 
adjacent bones, nat. size.—Chalk; near Maidstone. Enniskillen 
Collection (B. M. no. P. 4547). br., branchial arches ; chy., cerato- 
hyal; cl., clavicle; cop., copula; gu., hinder end of gular plate; 
icl., infraclavicle ; op., operculum ; sc., scapular arch. L7s. 
2. Ditto; upper part of left clavicle (cl.) and postclavicle (pel.), nat. size. 
—Turonmian zone; Lewes. Mantell Collection (B. M. no. 4270). 178. 
3. Ditto; fin-rays in side view from front (a) and in anterior view from 
hinder part (0) of caudal fin, showing denticles, nat. size.—Chalk, 
Kent. Mrs. Smith’s Collection (B. M. no. 49096). 180. 
4. Ditto; scales from anterior (a) and posterior ()) abdominal region, 
three times nat. size.—'l'uronian zone; Lewes. Mantell Collection 
(B. M. no. 4269). The large spinous tubercles in cross-section. 180. 
Ur 
Ditto; caudal scales, showing thickening for lateral line (/.) and hollow 
base of large median spimous tubercle, three times nat. size. 
Chalk ; Guildford. Capron Collection (B. M. no, 49832). 180. 
6. Ditto; head and adjacent parts of young individual showing smooth 
operculum (op.), nat. size.—Zone of Holaster subglobosus ; Dorking, 
Surrey. Capron Collection (B. M. no. 49837). 1S 
7. Ditto; small smooth operculum (op.) and upper end of clavicle (c/.), 
nat. size.—Zone of Holaster subglobosus ; Glynde, Sussex. Capron 
Collection (B. M. no. P. 10755). INS! 
8. Macropoma precursor, sp. noy.; left side view of head, with (8 @) upper 
view of cranial roof, nat. size, and (80) tubercular ornament of 
operculum, three times nat. size. The type specimen.—Zone of 
Schloenbachia varians ; Folkestone, Kent. B. M. no. 35700. d., 
dentary ; eth., ethmoidal dermal plates; /r., frontal ; op., operculum ; 
pa., parietal ; so., suborbital. isle 
9. Ditto; left side view of head, nat. size, with (9 a) tubercular ornament 
of operculum, three times nat. size.—Ibid. Beckles Collection 
(B. M. no. P. 6453). po.', po.’, wpper and lower post-orbital plates, 
displaced ; other letters as in fig. 8. ifteilk, 
10. Ditto; scales from the caudal region (a.) and thickening of a scale 
from the lateral line of the same region (b.), three times nat size.— 
Ibid. Gardner Collection (B. M. no. 47239). 182. 
