SPERMATOPHORES OF AMBYSTOMA PUNCTATUM. 20/ 



time when the stalk of the spermatophore is laid down, and these 

 spermatozoa owe the regularity of their distribution to the 

 papillated ridges of the cloaca. 



For comparison a drawing (Fig. 2) of a spermatophore of 

 Diemyctylus viridescens, obtained from a specimen in captivity, 

 is placed alongside the figure of the simple spermatophore of 



1 2 



Fig. I. Camera drawing of simple spermatophore of Aniby stoma pundatum, 

 X 5- In this and in the following figures the blackened portion is in nature snowy- 

 white. 



Fig. 2. Camera drawing of a spermatophore of Diemyctylus viridescens, X S- 



Amby stoma punctatum. (The spermatophore of Diemyctylus 

 has been previously described and figured by Jordan, '93.) 

 Several spermatophores of Diemyctylus viridescens were avail- 

 able for this study, but none of these differed essentially from 

 the one figured. The average dimensions of twelve simple sper- 

 matophores of Amhy stoma punctatum taken at random, and of 

 two uninjured spermatophores of Diemyctylus viridescens, are 

 as follows: 



Total Longest Diameter Smallest Diameter Breadth. 

 Height. of Sperm Mass. of Stalk. 



A. punctatum 6.2 mm. 3.7 mm. 2.5 mm. 6.4 mm. 



D. viridescens 8.0 " 2.5 " 0.3 " 12.0 



The simplest and most common case of compound spermato- 

 phore is that in which one spermatophore is deposited directly 

 on top of another (see Fig. 3). In the process of deposition of 

 the second spermatophore the sperm ball of the first one is 

 crushed into the form of an inverted cup covering the stalk of the 

 first, and the sides of this cup are stamped with a characteristic 



