NO. 1101. PROCEEDINGS OF THE NATIONAL MUSEUM. 91 



skulls of this species is the growth of median crests on the anterior 

 portion of the sagittal suture, and on the posterior extremity of the 

 nasals. This nasal crest is, so far as I am aware, unique among- 

 mammals. 



The teeth are but little worn in any of the specimens wliich I have 

 examined, wiiich would seem to indicate that they have a thicker coat 

 of euamel than those of Scalops, Scapamis, and Parascalops. In these 

 tbe teeth show the effects of attrition at a comparatively early stage.' 



THE TAIL AND NASAL DISK. 



It is a well-known fact that the tail of the star-nosed mole is subject 

 to a periodical enlargement. An individual in this condition was 

 described by Harlan in 1825 as a distinct species, but Godman recog- 

 nized the fact (in a publication of the same date-) that this charac- 

 ter was not specific. He stated that all the specimens with enlarged 

 tails which had been examined were males, and remarked: ''It is 

 most probable that the enlargement occurs only during the rutting 

 season." 



It now api)ears that Godman's opinion that the enlargement occurs 

 only in males is not correct. Of ten completely labeled specimens with 

 swollen tails which I have examined, five are males and five females. 

 The swollen condition lasts at least from Xoveniber to April, inclusive, 

 and probably a month longer in spring. The tail is not enlarged in 

 any of the specimens taken in the summer months. 



It is i)robably correct to look upon this enlargement of the tail as a 

 secondary sexual character, comparable to the growth of antlers in 

 deer. It affects both sexes, however, which is the exception rather 

 than the rule among deer. The enlargement occurs during the rutting 

 season, as Dr. Merriam has remarked,^ but the first litter is doubtless 

 born while the tail of the adults is in the enlarged condition. Though 

 the fact seems not to have been recorded, I judge from the examiiuitiou 

 of an immature individual that this first litter appears very early in 

 spring. Tliis being the case, there would still be time for the produc- 

 tion of a second litter while the tails of adults were enlarged, but if 

 more are produced, as Dr. Merriam states to be the fact, the later ones 

 would be brought forth after the enlarged condition had disappeared. 

 There are no observations, so far as I am aware, bearing directly on 

 this point. 



'A female from Williamstown, Massachusetts (No. 7469). contains 5 emljryos about 

 12 mm. long, three on the right side of the uterus and two on the left. The fetus is 

 rolled together in a compact form. The forefeet are ^iressed against the sides of the 

 muzzle witli the palms outward. The hind feet have the soles pressed together and 

 the tail is curled over them. The cutaneous processes of the nose are redexed over 

 the muzzle. 



- Journ. Phila. Acad., V, pt. 1, 1825, pp. 109-116. 



3 Trans. Linn. Soc. N. Y., II, p. 54. 



