374 



Leuciscus Apollonitis, Richardson. 



The difficulty of grouping and describing tlie numerous species of 

 this genus is acknowledged by all who have made the attempt. M. 

 Valenciennes has shown that the labours of Agassiz, Bonaparte and 

 other first-rate ichthyologists on the Leucisci have been by no means 

 successful, nor has he himself been more fortunate in his endeavours ; 

 the smaU groups of species described in the ' Histoire des Poissons ' 

 being far from suificiently precise to do away with the necessity of 

 revievving almost the whole genus before any member of it brought 

 from a new locality can be rightly placed. The entire question of 

 geographical distribution rests on the correct recognition of species ; 

 and a great advance in ichthyological science willbe made, when the 

 Cyprinoids of Asiatic Turkey, Persia, and Affghanistan shall be col- 

 lected and described, so as to complete the missing hnks between 

 the European and Indian forms. Enhghtened travellers, therefore, 

 Hke Mr. Poole, who bring home specimens of fi'eshwater fishes from 

 these countries, merit a grateful commendation from a Natūrai 

 History Society. The specimen that we have now particularly to 

 notice has a strong resemblance to the English Red-eye or Rudd, 

 the Rotengle of the French, and the Leuciscus erythrophthahnus of 

 Cuvier, which is the type of the subgenus Scardinius of Bonaparte. 

 In this group the mandible ascends obliquely in front of the upper 

 jaw, so that when the mouth is shut it forms the most anterior point 

 of the fish. It happens that Mr. Poole's specimen is exactly of the 

 šame size with the figure of the Rudd in Mr. Yarrell's beautifui 

 work, so that au exact comparison can be made between them, and 

 the most striking difference is that the Rudd has a sHghtly greater 

 height of body. The length of the head, the position of the dorsal 

 fin, the decurvature of the lateral hne, and the numbers of rays in 

 the fins, are the šame in both. The ventrals, hovvever, are a little 

 further forward in L. Apollonitis, so that the tips of the pectorala 

 overlap them a Uttle, and the scales are a trifle smaller, numbering 

 two more on the lateral line. In the Asiatic fish, moreover, the pro- 

 file from the point of the snont to the dorsal is less arched, being 

 uearly straiglit ; and the number of the pharyugeal teeth being dif- 

 ferent in the two species, we obtain a precise distinctive mark. Those 

 oi Apollonitis number five in the inferior or exterior row, all denticu- 

 lated within and hooked at the point ; while the three forming the 

 interior row are very short, and are likewise denticulated on their 

 interior sides. L. erythrophthahnus has only four teeth in the in- 

 ferior row. 



As in most Leucisci the second dorsal ray is unbrauched and 

 tapering, and the first, which is shorter, is applied closely to its base 

 •without the intervention of membrane. In this species the second 

 . ray is the tallest in the fin, and it is perfectly flexible, without any of 

 \hat stiffness which is characteristic of Agassiz' genus Rhodeus, in 

 which moreover the pharjmgeal teeth are chisel-shaped, The first 

 rav of the dorsal stands on the highest point of the back, and exactly 

 midway between the tip of the snout and the extremities of the 



