72 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



titioD, and it is mentioued here to sliow the greater general complete- 

 ness of development in these Eastern individuals. 



b. Series .slightly arched, not passing between nares. Two specimens, 

 large. In No. 3993 both onter segments are well separated from the 

 median; the tail is longer than head and body, and width of jaws 4.33 

 to line of groin. This individual is aberrant. 



c. Series angulated, not extending anterior to anterior margin of inner 

 nares. Nos. 3956, 2971, '3983, 3895, 3899, embracing five specimens, 

 three large ones, in Philadelphia Academy museum, and type of A. 

 ingens Green in same. 



This latter specimen is peculiar in some respects, as already noted, in 

 coloration. The head is relatively a little wider than in other specimens 

 of the same large size, the width entering the length to the groin four 

 times, as in individuals of the smaller average size of the species. The 

 length of the eye fissure enters 2.5 times the interorbital width, instead 

 of twice, thougb in one of equal size from Root River it enters 2.2 times. 

 The nares are not more than usually separated; hence the muzzle is 

 more contracted than usual. It is also depressed in profile, but not more 

 than in some other specimens. I believe it not to be a distinct species, 

 but a form dependent on causes similar to those producing others here 

 enumerated, and not more permanent than those, so long as those causes 

 are not universal. In other words, it is a large specimen, with teeth, 

 head, and tail of adult character, but body and muzzle more larval. The 

 fold on the hind leg and outer toe, mentioned by Green, is not marked, 

 or different from that seen in the species generally. 



ISTo. 4097, sixteen specimens from western Illinois; two have the serit^s 

 divided into four; 4093, two specimens; No. 4G91, Cook County, III., 

 thirty-four specimens; one has the three interruptions, and five, with 

 one of 4093, a median, making two series of teeth. 



Of the above the tongue is of normal size and the branchiae absorbed, 

 except in twelve specimens (No. 4691) of which five present stumps of 

 the branchiae; and two (4097) where both the tongue is very small and 

 the gill stumps remain. The width of the head is .25 to groin, and the 

 tail never longer than head and body. 



d. Median series arched, extending anterior to anterior margin of 

 inner nares. One specimen (3966) is fully developed in all other points. 



e. Palatine series angulated, extending anterior to inner nares' ante- 

 rior border. Nos. 4057, 3974, 3070, two of 4093, 3887, 3899&, four of 

 4097, nine of 4691. All of these have the short head and tail given in 

 the preliminary diagnosis. The small or larval tongue occurs in one of 

 4093, 3070, 3974, nine of 4691, two of 4097 ; branchial rudiments remain 

 in two of 4097 and nine of 4691. No. 4057 is remarkable in having a 

 very small tongue, and short deep tail, no stumps of branchiae, and 

 brilliant coloration, with large size and general adult appearance. It 

 compares with certain specimens (4693, 3984) of the form mavortium 

 in this strong retention of some larval characters, and, like them, is 

 from northern Minnesota, a region noted for its cold and late seasons. 



