134 Dr. E. Lonnberg on Binary Nomenclature. 



squarely truncated. Such a peuis was found in : — A. sylva- 

 ticus,^o 5. 5.1, Leicestershire (penis 6*4 X 2'4; testis 12 mm.); 

 74. 11. 25. 3, Shropshire (penis 6*2 x 2*4 : testis 12'5 mm.); 

 eight from Fortrose given to me by Mr. Ogilvie-Grant 

 (penis 4-2-6'5x 2-2'3 ; testis 12-14 mm.); A. favicollis 

 ivintoni, 8i. 1. 1. 4, Bishopstone, Hereford (penis 6'lx2"3; 

 testis 6 mm., shrivelled and collapsed) ; 94. 7. 23. 2-3, 

 Eszeli, Slavonia (penis Gx2*2; testis 12'5 mm,) ; A. s. di- 

 chrurus, 93. 9. 15. 6-7, Corsica (penis 5"5 x2"4 and 6x2'6 ; 

 testis 4 mm.) ; A. mj/stacinus, 77. 8. 13. 6-7 (penis 8x3*5 

 and 7x3 ; testis 15 and 14 mm.). 



It would seem from these facts that the complex type of 

 glans penis characterizes tlie youug, the simpler one the 

 adults of A. sylvaticus and allies. The retention of com- 

 plexity in a Villalba specimen with large testes may indicate 

 that such complexity is sometimes characteristic of species 

 or races ; it is to be hoped that adult spirit-specimens of the 

 island forms will be forthcoming, A complex glans is found 

 in CV^ce^^<s■^, a simple one in Ej/nm/sf and Murinaj gene- 

 ralh'^ and we may, perhaps^ regard the complex condition as 

 the more primitive in this group of rodents. In this con- 

 nection its presence in the young of Apodemus is a matter of 

 great interest ; and if such a primitive complex glans does 

 survive in the adult of any true murine, Apodemus is, 

 perhaps, one of the most likely genera to have such a species. 



XIX. — What is Binary Nomenclature'^ 

 By EiNAR LoxNBERG, Ph.D., F.M.Z.S., &c. 



No doubt most zoologists hoped that, since the International 

 Rules of Zoological Nomenclature had been adopted by the 

 International Zoological Congresses, the inconsistencies and 

 irregularities with regard to the scientific designation of 

 genera and species would cease within a short time. Of 

 course, some necessary alterations were expected, and would 

 cause troubles at first (that was foreseen!), but soon permanent 

 stability would prevail. Now several years have passed 

 since the adoption of these Rules, but everybody must admit 

 that we are still far from a fixed nomenclature. New and 



* TuUberg, ' Nagetliiere,' Taf. 1. %. 2. 

 t Op. cit. Taf. 1. fig. 16. 



