Holt and Calderwood — Report on the Rarer Fishes. 427 



apparatus). It is thus comparatively easy to distinguish the two species if 

 examples of the same sex are compared, but the difference between a mature male 

 of the smaller and an immature female of the larger species is not very con- 

 spicuous so far as these proportions are concerned. In this case, however, the 

 characters of the dorsal fin will serve to obviate any confusion. 



Since the proportions of the eye vary to some extent with the growth of the 

 fish it may be suj)posed that those which we have given above as characteristic of 

 the adult stages of C. lyra may not be available in distinguishing young examples 

 of this species from specimens of C. maciilatus of an equal size. As a matter of 

 fact, however, there is little risk of confusion, as we may illustrate by comparing 

 a mature female C. maculatus with the female C. lyra which, in our collection, 

 presents the nearest approach to it in size. The former measures 6-1 cm., and the 

 latter 5 "4 cm. (the caudal being excluded in both cases). As the proportion of 

 the eye varies in inverse ratio with the size of the individual, it is obvious that 

 the contrast will be less marked (the smaller specimen belonging to the species 

 characterised by the smaller eye) than if the two were of the same size. Still in 

 C. maculatus we find the eye "6 cm. and the snout (without the protractile mouth 

 apparatus) only '4 cm., whereas in C. lyra the dimensions are respectively "50 and 

 •55 cm. Thus in C. maculatus the eye is half as long again as the snout, which 

 in the other species exceeds the eye by one-tenth. Moreover, the distance 

 between the tip of the mandible and the vent is contained 24- times in the 

 total without the caudal in C. maculatus, in C. lyra only 2 times. The caudal 

 region is much thicker in the former, and the eyes much closer together ; and 

 although such actual approximation seems to some extent a feature of individual 

 variation, the width of the interorbital space relatively to the length of the eye is 

 always much less in C. maculatus than in 0. lyra. 



We note further that in a large series of C. lyra, of about the same size as, or 

 a little smaller than, the one we have been dealing with, the opercular trident is 

 constantly masked with skin except at the extremities of the denticles. In the 

 adults of C. maculatus, corresponding in size to these last, the trident is entirely 

 naked. The state of the specimens shows that this is natural, but a similar 

 condition might so easily manifest itself in abraded examples of 0. lyra that little 

 ■v^eight should be attached to the character in cases of doubtful identity. 



The brilliant colouration of the adult male of C. lyra is closely imitated, so far 

 as general tints are concerned, by the adult male of the smaller species. The latter, 

 however, is readily distinguished by the markings of the second dorsal fin alone. 

 On this fin there are four longitudinal rows of conspicuous dark spots, crossed by 

 a number of vertical rows of light markings, each with a narrow, dark outline. 

 The same fin in C. lyra merely exhibits four indistinct, dark, longitudinal bands. 

 The female of C. maculatus has the second dorsal profusely speckled with dark 



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