220 MERISTIC VARIA.TIOX. [part I. 



side, C. S. M., 628). m* was observed to be absent in the following : C. 

 lagopus, from Kamtschatka, absent on both sides in two cases 

 received in same consignment with 4 normal skulls. B. M., 88. 2. 20. 

 9 and 10; another case from Norway. Leyd. Mus. C. zerda : on left 

 side. C. S. M., 671. C. vulpes : ditto, 2 cases. B. M., 177, a and 

 175, b. C. viverrinus : on right side. Leyd. Mus. C. procyonoi- 

 des : ditto. Leyd. 3Ius. Hensel, I. c, gives the following : C. vulpes: 

 142 skulls; m? absent on both sides, 5 cases; on left side, 3 cases. C. 

 lupus : m? absent on left side, 2 cases ; on right side, 1 case. 



ICTICYON AND OTOCYON. 



* It is remarkable that in each of the two genera Icticyon and 



Otocyon, which are especially distinguished from Ganis by the 

 possession of unusual dental formulae, numerical Variation in the 

 teeth has been recorded, though the number of skulls of these 

 forms in Museums is very small. The two forms, besides, differ 

 from Canis in opposite ways, the one having a tooth less in each 

 jaw while the other has in each jaw a tooth more, so that the 

 presence of extra teeth in the two species is all the more im- 

 portant. 



255. Icticyon venaticus : according to the authorities has p£, m^, 

 viz. a molar less than the Dog in each jaw. The following skulls are 

 all that I have seen. The carnassials did not vary appreciably in the 

 three skulls. Each skull differs from the others, as follows. 



p±, «4, B. M., 185, a. 



»i, m~ - B. M. 185 b. 



p\\ mk /fc. S. M., 533. (See Flower, P. Z. S., 1880, p. 71.) 



25 G. Otocyon megalotis [ = lalandii and coffer'] : the usual formula 



is p^, mf, that is, one molar more than the Dog in each jaw. It occurs 



in 4 skulls at B. M. and in 2 at C. S. M. One specimen has in addi- 



4 — 4 

 tion an extra molar of good size in each upper jaw, giving m - -r. 



In this case w* is enlarged also on both sides. C. S. M., 675 (see Cat. 

 Mus. Coll. tiurg., Arc.). Three specimens having mf mentioned by 

 Doxitz, Sitzb. naturf. Fr. Berlin, 1872, p. 54. 



B. Domestic Dogs. 



Supernumerary Molars. 



257. Dogs. In 345 skulls the following 28 cases occurred, chiefly in 

 large breeds: 



"^ on both sides and v? on one side, 1 case. 



»^ on both sides 2 cases, 



w^ on one side 9 cases. 



nt? and m* on one side only 2 cases. 



mi on both sides 6 cases. 



;/; 4 on one side only 8 cases. 

 Hensel, Morph. Jahrb., 1879, v. p. 538. 



