254 



MUMSTIC VARIATION. 



[PART i. 



The above includes six Rkulls from Waigiu, the individual peculiarities of 



which aii- ^ivi-n In-low : 



The great variability of these skulls from the island of Waigiu is 

 very remarkable. The 4 Leyclen specimens were described by JEX- 

 TINK'. In one of these there was besides no left upper 2nd molar, 

 which was entirely absent without trace, leaving a diastema between 

 ///' and w 3 . In connexion with the variations of the dentition of P. 

 iitin-nlatus in Waigiu the following singular circumstance should be 

 mentioned. In all other localities the male P. iu<i<-i<l<ttnx alone is 

 sjiut ted with white, the female being without spots, but in Waigiu the 

 females are spotted like the males 2 . This curious fact was first noticed 

 by JKXTIXK (f. c., p. 111). 



In the other species of Phalanger no case of special importance met with ; but 

 since in P. umimts p ] is normally (4 skulls seen) two-rooted, it may be of interest 

 to note that such a two-rooted condition of p l was seen on both sides as a variation 

 in P. ornatus, B. M., 1317, b (2 other specimens having single-rooted p 1 ). 



*378. Trichosurus vulpecula ( Phnlnngistn milpina). The typical 

 form of this species is Australian, while the large variety, fuliginosa, 

 is peculiar to Tasmania. In the typical form no instance of absence of 

 P^ seen in 17 specimens examined. All possessed this tooth on each 

 side, and though varying a good deal in size, it was in every case well- 

 formed and functional, never being in a condition which could be called 

 rudimentary. 



Of the Tasnianian variety ful'Hjinosa, 18 specimens (8 in B. M., 10 

 in C. .M.) were examined. 



In G y 1 was present on both sides. 



1 right side only. 



1 left. 



2 J> } was absent altogether. C. M., 14 and /. 



Nevertheless in every case in which this tooth is present it is a large 

 tooth of about the size of the canines. In one case ^ is two-rooted on 

 each side, as (THOMAS, Cat. Marwp., p. ISO) in the Celebesian Phalan- 

 ger wainv*. C. M., 14 a, Hobart Town, Tasmania. 



Of the "intermediate" teeth in lower jaw one only is usually present, being 



I The small premolar was accidentally described in the paper referred to as 

 being between tin- ,-,/;,/> and p 4 , instead of 1, ( t\\r, n the anterior premolar aud /* 4 

 JKNTINK, in tin. 



- Coini.ai. the converse case of Hepialus humuli (tlu- Glmst Moth), of which. 



II """ ' localities, the males are -lear \\liite ,-ui.l the females are li"ht yellow- 

 brown with spots; l,,it in the Shetland Islands tlu- males are like the females 



:'li in NHI-VIM- degrees. See JKNM.K Wi.n;. Entin<.l,> ; ii*t. IssO, p. 251, PI 



