oOG Mr. P. Sclnuldt on the 



All the specimens of our collection attributed by nie to 

 /A ehis,'^o<ioii (hilnus are 300-i31 mm. long, and in the smaller 

 specimens I have never found such deveioiMuent of canine- 

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

 duhius is nothing more tiian older specimens of H, elassodon. 

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

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

 tion are liom Tartar tStrait (North Japanese Sea). It may 

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

 consider it for the present. 



The forms Ilippofflosaoides elassodon elassodon and 11. elasso- 

 don robustus can be distinguished by the number of rays in 

 dorsal and anal. I attribute to the forma ty[iica specimens 

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

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

 tion we tind the following distribution: — 



Htppofflossoides elassodo7i 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 //. 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 neaily 

 connected forms of one species. 



In otlier 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 tlie Atlantic 

 and Pacific .«pecies of Hippofflossokles -Rill be published in my monograph 

 of Russian Ileterosomata, forming a volume of ' Faune de la Kussie,' 

 published by the Imperial Academy of Sciences of Petrograd. 



1 



