NO. 1101. PEOCEEDINGS OF THE NATIONAL MUSEUM. 33 



rupecls of Nortli America^ does not differ in color from ordinary speci- 

 mens of S. aquaticiis from Xew York. 



Within recent years three forms of Scalops have been described. 

 These are the S. aquaticus australts of Chapman,- the *S'. parruH of 

 Khoads,^ and the >S'. texanns of Dr. J. A. Allen.^ Dr. Allen's species is 

 from the coast of Texas and the other forms are from Florida. I have 

 not been able to determine the rehitionship of these forms to my entire 

 satisfaction, chiefly owing to a lack of specimens from the southern 

 portion of the Gnlf States. 



:Mr. Chapman's Florida form amiraUs was tirst described. His diag- 

 nosis includes but two characters, thus: " Similar to Scalops aqtiaficns, 

 but averaging slightly browner and constantly much smaller."^ 



I have examined the type and several other skins and alcoholic speci- 

 mens from the type locality (Gainesville) and other parts of eastern 

 Florida. While the small size of the adults as compared with speci- 

 mens from farther north on the Atlantic Coast is conspicuous, the 

 difference in shade of color is scarcely perceptible. As regards si/e, I 

 have shown in another place (p. 29) that there is a gradual diminution 

 on the Atlantic Coast from north to south. 



The skull of amtr<ilis when tirst examined, seems very different from 

 the typical form, on account of its small size and delicate structure. 

 Perhaps the most noticeable feature is the form of the coronoid process 

 of the mandible. This presents a real difference from that found in 

 New York and Pennsylvania specimens. In this latter the coronoid is 

 heavy and not strongly uncinate, and has a supplementary niammiforin 

 process on the posterior margin below the extremity. In Florida spec- 

 imens the coronoid is slender and strongly uncinate and the second- 

 ary process is wanting. There is, however, a gradation in this charac- 

 ter. In Maryland and Virginia about as many mandibles have the 

 secondary process as are without it, and in the Carolinas it is (|uite 

 rarely present. 



From Mr. Chapman's comparative measurements (though he does not 

 refer to the fact), it would api)ear that the hind foot is proportionately 

 shorter in australis than in typical aqi(aticu.s. 



Very careful measurements of some alcoholic si>ecimens of adults, 

 however, convince that the reverse is the truth, i. e., that the Florida 

 form has the longer foot relatively, though it is, of course, absolutely 

 shorter. The following table brings out this fact and some others in 

 connection with proportions. I chose the proportion of the head to 

 the tail and foot alter many trials, and believe it to be reliable. 



1 Plate 150. 



-Bull. Anier. Mus. Nat. Hist., V, 1893, p. 339. 

 "Proc. Acad. Nat. Sci. Pbila, 1894, p. 157. 

 ^Bull. Amer. Mus. Nat. Hist.. Ill, 1891, p. 221. 

 Proc. N. M. vol. xix 3 



