1. CENTBISCUS. 521 



The soft dorsal fin is higher than long, with the rajs simple, the 

 middle ones being the longest ; its distance from the caudal equals 

 the length of its base. The anal fin commences immediately behind 

 the vent, vertically below the fourth dorsal spine, and extends a little 

 more backwards than the soft dorsal ; it is, Hke that fin, composed of 

 simple rays, but much lower. The caudal fin is shorter than the 

 pectoral, slightly emarginate posteriorly, and composed of nine rather 

 compressed and undivided rays, the others on the upper and lower 

 sides of its base being rudimentary. 



The colour of the specimens is rose or reddish-olive on the back, 

 and silvery on the sides and on the beUy. 



The vertebral column is composed of eight abdominal and sixteen 

 caudal vertebrae ; the former are distinguished by their strength and 

 large size, a peculiarity which is in intimate connexion with the cir- 

 cumstance that they form the base of other strongly developed bones ; 

 their parapophyses are strong, rather long, and those of the first foiir 

 vertebrae have their extremities united. The bony strips, which are 

 visible externally, and which we have mentioned in the description 

 of the outward characters, are the modified ribs with their epipleurals. 

 The neural spines of the three anterior vertebrae are strong, espe- 

 cially that of the third, which corresponds to the interneural of the 

 second dorsal spine. This interneural is situated behind the third 

 neural, and ends in three articular processes which receive two others 

 of the dorsal spine between them. 



Another pecuUaiity is the great breadth of the radius, this bone 

 forming with its fellow a suture which is as long as the bone is high ; 

 there is an oval free space between the radius and the humerus. 

 The coracoid is very strong, straight, sabre-shaped, extending back- 

 wards to the pubic bones, which, however, are not fixed to it and 

 quite small. The bony plates forming the cutting margin of the 

 abdomen and thorax are dermal productions, and do not belong to 

 the skeleton. 



2. Centriscus gracilis. 



Lowe, Proc. Zool. Soc. 1839, p. 86, and Trans. Zool. Sac. iii. p. 12. 



B.4. D. 4-5 I 11. A. 18-19. P. 16. V. 5. C. 6-1-4 + 5 + 6. 



The height of the body is contained twice and three-fifths to three 

 times in the distance of the operculum from the base of the caudal 

 fin. The second dorsal spine is rather strong, not (or very indi- 

 stinctly) denticulated posteriorly, its length being one-fourth or two- 

 ninths of the distance of the opercle from the caudal. 



Sea of Madeira. West coast of Africa. Coasts of Japan and 

 China. 



a-c. Half-grown. Mediterranean. Purchased of Mr. Frank. 

 d. Adult. ? Mediterranean. P«rchased of Mr. Jamrach. 

 «. Adult. Madeira. Presented by the Rev. H. H. Methuen. 

 /, g. Fine specimens. Sierra Leone- 

 h, i. Fine specimens. Japan. 



