NO. I 



SCALUS OF AFRICAN FISHES — COCKERELL 



This type of basal radii thus runs through the Haplomi, Acan- 

 thopterygii and Percesoces ; yet it is wholly absent in the Scorn- 

 brids, so far as I know, and Gadus {cf. H. W. Marett Tims, Quart. 

 Journ. Micr. Science, Oct., 1905) shows nothing of it. (The scale 

 of Gadtts is curiously like that of Catostonius.) The ctenoid features 

 found in Aiiabas seem to be traceable to a Berycid source. It is evi- 

 dent, of course, that no Acanthopterygian fish can be derived from 

 any Characinid stock, but it is suggested that the basal folding was 

 developed among the Malacopterygians (Alosa shows it sufficiently 

 well) and carried thence to the Characinid and Acanthopterygian 

 (or Haplomid) ancestors. 



I hope in some later contribution to compare the South American 

 Characinid scales with the African. At present I cannot do this 

 for lack of material, 

 but the little I know 

 suggests that there 

 may be little resem- 

 blance between them. 

 (Figure 2 (drawn by 

 Miss Evelyn V. 

 Moore) .shows the 

 scale of Cheirodon 

 insignis Steindachner 

 from Panama ; this 

 fish is placed by Bou- 

 lenger in the Plydro- 



cyoninse, but it will be seen that there is no resemblance to the scales 

 of any of the African members of that subfamily. The scale of 

 Luciocharax is quite unlike anything African, but this belongs to an 

 exclusively American subfamily (Xiphostominas). 



For the means of obtaining the photographic figures (the work 

 of Mr. T. C. Black, of Boulder, Colorado) I am indebted to a grant 

 from the American Association for the Advancement of Science. 

 It may be worth while to state that in order to get good photographs 

 the scales must be mounted dry. When placed in balsam many of 

 the characters are obscured. 



Fic. 2. Cheirodon insignis Steindachner 



HYDROCYONIN^ 



The scales of tlie African Hydrocyoninse fall naturally into three groups : 

 (i) Sarcodaces group, in which the approximately circular scales have fine and 

 rather numerous radii, and the circular sculpture is very distinct, the 

 apical circuli very coarse and quite different from the basal and lateral. 

 S. odoe examined. 



