E. LÖNNBERG, MAMMALOGY OF ECUADOR. 73 



be well seen below as well as on the upper side. Some few 

 longer bairs protrude beyond tbe tip of the tail from the 

 lower side. The feet are more fully described below from 

 alcoholic specimens, but it may be remarked here, that, 

 unlike the condition foiind in C. fuliginosus, the fingers are 

 nearly quite naked above. 



The measurements of the skull of the specimen from 

 Gualea are recorded below and from these can be seen, that 

 the three anterior large molars have a considerably greater 

 size than the corresponding ones of C. fuliginosus. This is of 

 course very important, and also recently pointed out by 

 Thoiaias as one of the chief characteristics distinguishing the 

 two species. But there are other differences as well, which 

 are not visible from a study of the table of measurements. 

 One of these, also remarked by Thomas and confirmed in 

 this case, is, that the anteorbital vacuities are completely 

 filled with bone, which is the 'more striking, as this specimen 

 is decidedly younger than the adult or partly even old spe- 

 cimens of G. juliginosus, with which it bas been compared, 

 but in which these vacuities stånd open. The zygomata of 

 C. obscurus are decidedly more slender than in G. fuliginosus.^ 



Cranial measurements of Gaenolestes obscurus ^ 

 from Gualea: 



Total length 30,0 mm 



Greatest length of nasals 13,3 » 



Interorbital breadth 7,5 » 



Length of palate (to tip of premax.) . . 16,3 » 



» » foramina incisiva (ant. pal.) . 6,0 » 



Combined length of m^ — m^ 6,3 » 



Lower jaw, tip of i^ to cond3do . . . 22,8 » 



From these descriptions above it may be seen 1. that 

 this coUection contains two quite different species of Gaeno- 

 hstes, 2. that these according to their respective characte- 

 ristics agree with G. fuliginosus and G. obscurus, and 3. that 



^ Thomas has stated recently (1920) that Orolestes has a more com- 

 pressed zygomatic arch especially anteriorly than Caenolestes, but although 

 this undoubtedly is true, it may be observed that the middle of the zygo- 

 ma of C. fuliginosus also is rather flattened, as its height is 1,5 mm, 

 but its thickness only between 0,3 and 0,4 mm. 



