No. 2.] AMPHIUMA MEANS. 397 



The transverse trabeculae in the cardiac region are ten milli- 

 metres apart, and are thrice as heavy as the longitudinal tra- 

 beculae. Immediately anterior to the front limbs is seen a 

 spiracle guarded by membranous flaps to exclude the mud. 

 This aperture is in communication with the pharynx, and is 

 supplied with special muscles for closing it, as previously 

 described. 



Having now called attention to the important features of 

 the adult, it is in order to make a brief examination of the 

 young. 



The Young Amp/mima. 



For a long time embryologists have been seeking a good 

 supply of specimens representing the development of this pecu- 

 liar Amphibian. Hay (2) was successful in finding the eggs 

 of Amp/muna in an Arkansas swamp in 1887. This material 

 furnished important information. Last February I was so for- 

 tunate as to secure a number of very young specimens from a 

 North Carolina dealer. They ranged in length from sixty- 

 eight to ninety millimetres. They were found in a damp 

 locality under some large rocks. Hay's embryos were 45 mm, 

 long. It is probable that my specimens were hatched in No- 

 vember or December. The general shape of the young (Fig. 12) 

 is very much the same as the adult. There are no signs of 

 gills, and only one gill-opening persists on each side. The 

 eyes are rendered useless by the heavy shields of epidermis, 

 as in the adult. The dennal glands aj'c more prominent than 

 in the old. The caudal fin is less atrophied. The lower jaw 

 is correspondingly shorter than the adult's. The projecting 

 dermal folds of the upper jaw are little developed. TJie legs 

 are relatively longer tJian in tJie adult, but the digits are imper- 

 fectly fortned, those Oft the hind limb being qjnte distinct, while 

 there are no signs of any on the fore limb. Hay (3) states the 

 reverse of this to be true in his embryos, viz., that the digits 

 of the fore limbs are better differentiated than those of the 

 hind. A gross dissection of this small specimen showed that 

 the internal structure accorded with that of the adult, except 

 in the case of the left lung, which did not extend to the caudal 



