2^-i ^li'. C. T. Regnn on the Analomy and 



Jrroriited with black and white scales: secoi;danes similar to 

 i\iQ primaries, with a large brown spot at the anal angle; the 

 marginal line black ; the fringe white. Underside greenisii 

 white : primaries with a wnde submarginal black band ex- 

 tending from near the apex to the anal angle : secondaries 

 Avith a large black spot at the anal angle. 



Expa-.ise If inch. 



Ilab. Peru, La Union, Rio Huacamaya, Carabaya, 

 2000 [eet {Mus. I)nic,). 



Allied to Racheospila calliope, Druce, fiom Mexico, but 

 very distinct. 



XXXII. — The Anatomy o.nd Classification of the Teleostean 

 Fishes of the Order SalmojJercce. By C. TATii Regan, M.A. 



(Publislied by permission of the Trustees of the British Museum.) 

 The order Salmopercse includes only three genera — Percojjsis, 

 Columbia, and Aphredoderus — each with a single species, 

 little fishes of the fresh waters of North America. It is an 

 isolated group, showing resemblances to the Iniomi, Micro- 

 cyprini, and Jierycomorphi^ but quite distinct from them all. 

 The following description is based on examples of all three 

 species : — 



External characters. — Body moderately elongate, com- 

 pressed, covered with adherent ciliated scales; lateral line 

 complete, running along middle of side. Mouth rather 

 small, terminal or subterminal, not or scarcely protractile, 

 bordered above mainly by the praemaxillaries ; maxillary 

 concealed or slightly exposed distally, without supramaxillary ; 

 small villiform teeth in thejaws. Head with large muciferous 

 cavities ; interorbital region flattish ; eyes lateral ; two 

 nostrils on each side. Gill-membranes attached to isthmus; 

 6 branchiostegals ; 4 gills; pseudobranchige. Dorsal fin 

 median, of 2 to 4 spines and 9 to 11 soft rays ; anal of 1 or 

 2 spines and 6 or 7 soft rays ; caudal with 18 or 19 principal 

 rays, 16 or 17 branched ; pectorals lateral ; pelvics sub- 

 abdominal, each of 7 or 8 rays, the outermost simple and with 

 a rudimentary spine adnate to its basal part. 



Air-bladder. — The Salmoperca? are pliysoclistic ; I cannot 

 find any trace of a pneumatic duct. In this I am confirmed 

 by Dr. W. G. Ridewood, who kindly examined an example 

 of Cohimbia transmontana. 



Head- skeleton. — There are no parietal crests and the 

 occipital crest is developed only on the posterior face of the 

 skull; the posterior temporal fossse are open above j the 



