during their Growth mid Development. 115 



especially from the West Indies ; and these, considering the 

 difficulty of distinguishing from each other the species be- 

 longing to these genera, merit some attention. The youngest 

 individuals with no scales or lateral line, and with a spinous 

 prgeoperculum, certainly do not present any character which 

 enables us to decide whether they are Trachuri or Caranges. 

 The species in which I have observed the greatest changes 

 during growth and development is C. armatus 5 but they are 

 already in great part well known, and I shall not here examine 

 them in more detail. These changes are, however, very in- 

 ferior to those observed in the Gcdlichthyes^ which have been 

 divided into more genera than there are species in reality, 

 because the successive stages which recur in an analogous 

 manner in the different species have been interpreted as con- 

 stituting so many separate generic types — the result of which 

 has naturally been that the diagnoses of the species have be- 

 come as incorrect as possible, and that systematic confusion 

 has attained its final limits. Each of the three or four exist- 

 ing species passes through a phase of Blepharis {Gallichthys), 

 one of Scyrisj and one of Hynnis. Hynnis goreensis is thus 

 the adult form of Gallichthys cegyptiacus and of Scyris alex- 

 andrinus ; the forms described by Poey under the names of 

 Scyris analis and Hynnis cuhensis correspond in the same way 

 to G. (Blepharis) crinitus. The Scyris phase belonging to 

 G. ciliaris has not been before described. It may be asked 

 (but, owing to the want of sufficient materials, I cannot decide 

 the question) whether G. ciliaris of the Indian Ocean 

 diffi^rs specifically from the American G. crinitus. If these 

 two forms, comparatively rare in the adult state, are, as I 

 suppose, fishes which inhabit tolerably deep water, we can 

 understand that the same species might occur in seas far dis- 

 tant from each other. The general rule which finds its ex- 

 pression in the changes of form produced in this genus may 

 be summed up as follows : — Greater and greater elongation 

 of the body, so that its original proportions are completely 

 altered ; reduction of the number of spinous rays in the dorsal 

 and anal fins, as also of the filamentous prolongations of the 

 ventrals, and, later on, likewise of those of the dorsal and 

 anal. 



Exactly similar changes occur in the genus Selene, Lac. 

 (p. p.) ( = Argyreiosus, Vomer, Platysomus) ; and in conse- 

 quence " analogy " and " affinity " have been until very 

 lately confounded in them as in Gallichthys ; nay, more, 

 after Dr. GUnther had elucidated the filiation of the forms in 

 the essential points, the justice of his views was contested, 

 and the error again maintained with a certain emphasis. 



