THE BATRACHIA OF NOKTH AMERICA. 63 



AMBLYSTOMA COPEANUM Hay. 



Proceedings U. S. National Museum, 1885, p. 20'J, PI. xiv. 



The bead is large, somewhat wider thau the body, aud llattened; the 

 body short, and the tail long and compressed. The skin is for the most 

 part smooth, bat everywhere, as seen under a lens, is pitted with the 

 openings of the cutaneous follicles. Of these, there are a few enlarged 

 ones in a band surrounding tlie orbit and extending forward to the 

 nostril. Others are found above the angle of the jaw, and a few still 

 larger ones on the posterior border of the parotoid region. The promi- 

 nent keel and the whole tip of the tail are so richly provided with 

 enlarged pores as to present a granulated appearance. 



The width of the head is somewhat greater than that of the body. It 

 is possible that the breadth aud flatness of the head have been exag- 

 gerated somewhat by the injuries that it has received; but this can be 

 true only to a very slight extent. The breadth is about the same at the 

 angle of the jaw aud the corner of the mouth. From the former point 

 the head tapers backward, the outline being concave to its posterior 

 border, where it is suddenly constricted into the neck. From the cor- 

 ners of the mouth the head tapers forward to nearly opposite the nostrils, 

 beyond which it is rapidly rounded to form the snout. The width of 

 the head is a little less than the distance from the snout to the gular 

 fold, and is contained in the distance from the snout to the groin 3.6 

 times. The distance to the gular fold is contained in the distance to the 

 groin 3.2 times. The depth of the head, on a line joining the angles 

 of the jaws, is a little less than one half its width. The gular fold does 

 not overlap, as it does in some species. It may have done so in life, 

 but manipulation of the skin fails to restore an overlapping fold. The 

 upper jaw projects beyond the lower. Eyes of moderate size. External 

 nares small; their distance apart somewhat less than the width of the 

 interorbital space. 



The tongue is not notably different from that of A. tigrinum. The 

 teeth are arranged in four series, which together form an inverted \/, 

 the angle of which is very obtuse. The limbs of the V? as seen with the 

 unaided eye, appear nearly straight, and are seen to extend beyond the 

 internal nares along their external fissure. Examination with a lens 

 proves that the inner series are each slightly /-««^ shaped, and so disposed 

 as to make the angle of the V rounded off. The outer series on each side 

 is nearly as long as the corresponding inner series ; is plainly separated 

 from it, aud nearly straight or slightly concave on the posterior side. 

 Inner nares more distant than the external. The body is somewhat 

 depressed, but has not the swollen appearance presented by A. opactim. 

 The distance from the snout to the axilla is just equal to that from the 

 axilla to the groin. There are eleven well-marked costal grooves. There 

 is a median furrow, not deep but distinct, beginning on the occiput 

 and running ali)n;4tuo back, deepening on the sacral region, aud ending 

 over the middle of the veut, at the commencement of the caudal crest. 



