Miscellaneous. 71 



Length of maxillary 1^- 



of base of dorsal fin 3£ 



of pectoral fin 2\ 



of base of pectoral fin \ 



of ventral fin 1 \ 



of base of anal fin -| 



of third anal spine ^$ 



of caudal fin l^j- 



Distance of vertical of vent from snout 5|- 



Fam. Percid^e. 



Priacanthus insularum, sp. n. 



D. 10. 15. A. 3. 15. Scales of lateral line, about 76. 



This species has a close resemblance to P. macrophthalmus, from 

 which, however, the following differences distinguish it: — 1. The 

 height of the body to the total length is as 1 to 3|, not as 1 to 2|. 

 2. The diameter of the eye is to the length of the head as 1 to 3^, 

 not as 1 to 2|. 3. The number of soft rays in the dorsal fin is 15, 

 not 13 or 14. 4. The length of the second dorsal spine is to the 

 last as 1 to 2, not as 1 to If . 5. The edge of the opercle has one 

 flat spine, and above this there is a rounded plate ; whereas the edge 

 of the opercle of P. macrophthalmus has two flat spines. 6. In P. 

 macrophthalmus the two borders of the preopercle form a right angle, 

 and the margins are strongly denticulated. In the present species 

 the angle formed by the free borders of the preopercle is obtuse, and 

 the margins are very finely serrate. 7. The caudal is slightly emar- 

 ginate. 8. The fins have not black edges, as is the case with P. 

 macrophthalmus. 



This species is established on a single specimen, taken last May, 

 which had a length of 14^ inches, and a height of 3f, the head being 

 3£ inches long. The eye had a diameter of 1^ inch. The example 

 was coloured a uniform red, and it is now in the British Museum. 



MISCELLANEOUS. 



Use of the Weights and Measures of the Metric System in Scientific 



Pursuits. 



On the 18th of November last, a numerous deputation, composed 

 of individuals of great eminence and belonging to various occupations 

 and professions, waited on the Fit. Hon. Milner Gibson, M.P., Pre- 

 sident of the Board of Trade, for the purpose of representing the 

 expediency of carrying into effect the recommendations of the Com- 

 mittee of the House of Commons which was appointed last session 

 to consider the advantages of an international system of weights and 

 measures. This Committee, after a long and careful investigation of 

 the whole question, had unanimously resolved to recommend the 

 adoption, for all purposes and throughout the British Empire, of the 

 weights and measures of the metric system. Mr. Wm. Ewart, 

 as Chairman of the Committee, introduced the deputation to the 

 minister, who listened to all the speakers with the greatest attention 

 and courtesy, and returned a very encouraging answer. 



The claims of natural history were advocated by Professor Owen, 



