24 Proceedings of the Biological Society of Washington. 



to tip. Winter pelage: Darker and more grayish than summer pelage. 

 Tending to be more brownish than corresponding pelage of S. o. longi- 

 cauda. Upperparts most nearly between chaetura drab and fuscous black; 

 underparts and tail essentially as in summer. 



Skull. — Broad, flat and rather massive for the species obscurus. Slightly 

 more flattened than that of S. o. longicauda, less depressed interorbitally, 

 the braincase flatter and arising somewhat less abruptly in the frontal 

 region, superior portion of rostrum broader and more flattened, lachrymal 

 foramen smaller, unicuspidate teeth narrower, dental pigmentation less 

 extensive. Larger, broader interorbitally, with broader, longer rostrum, 

 and more deeply pigmented and heavier dentition than in S. o. elassodon. 

 Larger than that of S. o. alascensis, more flattened, averaging broader 

 interorbitally, with relatively longer palate and heavier dentition. 



Measurements. — Type (adult female): Total length, 120; tail vertebrae 

 56; hind foot, 15. Skull: Type (adult female; teeth slightly worn) : Condy- 

 lobasal length, 18.4; palatal length, 7.3; breadth of cranium, 8.8; inter- 

 orbital breadth, 3.8; maxillary breadth, 5.3; maxillary tooth row (anterior 

 edge of second upper incisor to posterior edge of last upper molar measured 

 at alveolar border), 6.6. 



Remarks. — Nine specimens of Sorex obscurus malitiosus are in the series 

 from the type locality. These are fairly constant in their characteristics 

 and represent an island form which is probably confined to Warren Island. 

 In the flatness of its skull malitiosus shows its nearest tendency toward 

 S. o. elassodon, but on the whole the form is more like S. o. longicauda 

 than any other subspecies. Its geographic range, however, is separated 

 from that of longicauda by the range of S. o. elassodon which seems to 

 occur on most of the islands between Admiralty Island, Alaska, and 

 Moresby Island, British Columbia. 



