Systematic Arrangement of the Family Salmonidoe. 405 



This remarkable insect bears a MS. name of P. Cameron's, 

 ''Prosopis papuaiia." It is greatly to be regretted that the 

 2 of this species is unknown, since we are still in ignorance 

 as to whether the tongue is short and blunt as in that sex of 

 Palceorhiza anl both sexes of Prosopis, &c., or acute as in 

 the cJ here described. 



XLVI. — T/ie Systematic Arrang meat of the Fishes of the 

 Family Sahnonidie. By C. Tate Uegan, M.A. 



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



In a recent synopsis of the families of Salmonoid fishes 

 (Trans. R. Soc. Edinburgh^ xlix. 1913, p. 289) I have shown 

 that the SalmonidaJ are well distinguished from the Smelts 

 (Osmeridas), Sil-smelts (Argentiliidai), &.C., by osteological 

 characters ; perhaps the most noticeable of these is that the 

 vertebra} turn upwards at the base of the caudal fin in the 

 Salmonidaj, but in no other Salmonoids. As thus restricted 

 they form a natural group, confined to the coasts and rivers 

 of the Arctic and North Temperate zones. 



After a study of a large series of skeletons, I have arrived 

 at certain conclusions as to the number of genera that may 

 be defined, and as to their natural affinities, which are 

 embodied in the following syno[)sis : — 



Synopsis of the Genera. 



I. Parietalfl not meetin<if in middle line. Teeth well developed in jaw,^, 

 ou vomer and palatines, and iu a double series on tongue. Scales 

 small, 19 or mure in a transverse series from origin of dorsal fin 

 to lateral line. Dorsal tin short, with not more than IG ray.«, 12 

 or fewer branched. {Salmonince.) 



A. A double or zigzag series of teeth along shaft of vomer, some- 

 times deciduous iu the adult .... 1. Salmo, Linn. 



]3. Teeth only on head of vomer, which has a boat-shaped depression 

 behind it. 



Vomerine teeth in a V-shaped or Y-shaped 



group, separatetl from tlie palatine teeth. 2. Sulcclinus, Nilss. 



Vomerine teeth in a curved, nearly semi- 

 circular series that connects the pala- 

 tine series ; mouth large ; teeth strong, ■j. llncha, (\i\uih. 



Vomerine teeth in a transverse series that 

 connects the palalino series; mouth 

 rather small; teeth rather weak .... 1. L'lac/ij/nii/sla.r, (.innlh. 



