30G Mr. P. Schmidt on the 



All the specimens of our collection attributed by me to 

 II. elassodon dubius are 300-431 mm. long, and in the smaller 

 specimens I have never found such development of canine- 

 like teeth. Therefore it may be supposed that II. elassodon 

 dubius is nothing more than older specimens of H. elassodon. 

 But, on the other hand, we see that this form is restricted to 

 a separate geographical area : all the specimens of our collec- 

 tion are fiom Tartar /Strait (North Japanese Sea). It may 

 be, therefore, that it is a distinct subspecies, and as such I 

 consider it for the present. 



The forms Hippoglossoides elassodon elassodon and II. elasso- 

 don robustus can be distinguished by the number of rays in 

 dorsal and anal. I attribute to the forma typica specimens 

 having D. 77-86, A. 60-69, and to Hippoglossoides elassodon 

 robustus specimens with D. 67-75, A. 51-59. In our collec- 

 tion we find the following distribution : — 



Hippoglossoides elassodoti elassodon. 



D. 76 79 81 82 83 84 85 86 rays. 



11442122 specimens. 



A. 60 61 62 63 64 66 67 68 69 rays. 



121432211 specimens. 



Hippoglossoides elassodon robustus. 



D. 67 68 69 71 72 73 74 75 76 77 rays. 



1213111211 specimens. 



A. 51 52 53 54 55 56 57 59 rays. 



11132122 specimens. 



The specimens of H. elassodon robustus having D. 76 and 

 1). 77 could be attributed to H. elassodon elassodon, but they 

 have at the same time a very low number of anal rays (A. 57, 

 A. 59), and must be regarded therefore as transitional forms. 

 This Table demonstrates sufficiently clearly that we have here 

 only one variation row with two maximums, i. e. two nearly 

 connected forms of one species. 



In other respects both forms are also nearly connected, as 

 is shown in Table II.* (p. 303), representing the chief 

 features. 



* This Table is only an extract of the results of my measurements. 

 More complete tables, detailed diagnoses, and synonymy of the Atlantic 

 and Pacific species of Hippoglossoides will be published in raj monograph 

 of Russian Heterosomata, forming a volume of ' Faune de la Eussie/ 

 published by the Imperial Academy of Sciences of Petrograd. 



