CHORINEMUS. 63 



There is one remarkable peculiarity regarding this fish which does not appear to have 

 been observed. The second dorsal has a narrow scaly band along the base of the 

 anterior portion. It is continuous with the line of the back as far as the seventh ray, 

 when it takes an upward course, leaving a clear space between it and the line of the 

 back; it diminishes gradually in length till it stops before the upper third of the 

 fifteenth ray. The anal has a similar band, which terminates before the eighth ray. 



Seychelles. Amboyna. Madras. 



NAUCRATES, Cuv. 



204. Naucrates ductor. [691.] 

 For synonymy see Giinther, Fish. vol. ii. pp. 374, 469. 



It has already been maintained by Gill and Kner that Nauclerus, Cuv. & Val., com- 

 prises the young specimens of Naucrates ductor, an opinion which, from the examination 

 of several specimens in the British Museum and one from the east coast of Africa, 

 proves to be quite correct. The armature of the praeoperculum, which has been used 

 by Cuvier for the distinction of various species, is found in very small examples only ; it 

 is very apparent in specimens an inch long, while it has disappeared in others of 2 inches. 

 This armature is evidently subject to slight variations, and it is not impossible that all 

 the six species of Nauclerus distinguished by Cuvier are referable to one or, at the 

 outside, to two species of Naucrates. 



A second question arises, whether Naucrates should be referred to Scombridce or 

 Carangidce. The two anal spines of the young are separate from the soft portion ; and 

 although the number of caudal vertebrae is increased by two, yet the number of ab- 

 dominal vertebras remains the same : we are therefore inclined to remove this genus 

 from the Scombridce to the Carangidce. 



The specimen from the east coast of Africa corresponds entirely with Cuvier's de- 

 scription of Nauclerus abbreviatus. The caudal keels are not developed. 



East coast of Africa. All the seas of temperate and tropical regions. 



CHOEINEMUS, Cuv. & Val* 



205. Chorinemus lysan. [639.] 

 Scomber lysan, Forsk. no. 67. pi. 54. 



Russell, ii. p. 31, pi. 141. 



Licliia lysan, RUpp. Atl. Fische, p. 91. 



Chorinemus commersonianus, Cuv. fy Val. viii. p. 370. 



lyzan, Cuv. $ Val. viii. p. 387; RUpp. N. W. Fische, p. 44; Cantor, Mai. Fish. p. 118. 



lysan, Gilnth. Fish. ii. p. 471; Kner, Novara, Fisch. p. 163. 



Zanzibar. From the Bed Sea to the north-tvest coast of Australia. 



* Undetermined specimen [2G0]. 



