96 CALIFORNIA ACADEMY OF SCIENCES. [3D Ser., 



the base of the tail of the female very nearly over her cloaca. 

 In several instances, a notable one being that mentioned 

 above, where a large quantity of sperm was found in the 

 cloaca of the female, these lips have been so much extended 

 as to reach fully half way down across the tail of the female. 

 One is reminded of a saddle on a horse's back. At such 

 times the ruga? on the inner surface of the lips (fig. 10) are 

 very prominent. They project beyond the edge of the lips 

 all around the cloaca in the form of a fringe, and are quite 

 conspicuous in contrast with the dark color of the outer 

 skin, they being a lively pink, owing to their great vascu- 

 larity. 



Whether or not this condition may be in some way con- 

 nected with the transference of the sperm to the female 

 cloaca, I am unable to say; but it seems very possible. And 

 this conjecture is supported by what has been observed con- 

 cerning the nature of the sperm masses. 



From my present knowledge these would be more prop- 

 erly called drops of semen than spermatophores. 



I have seen masses of this kind on three occasions : one 

 was deposited on the floor of the aquarium by a captive 

 male; another was taken from the cloaca of a male; and 

 the third was taken from the cloaca of the copulating female 

 already spoken of. 



The structure and appearance in each instance were the 

 same. They were semifluid, and hence without definite 

 form, and were semitransparent, though not uniform in 

 color throughout, they being more opaque and somewhat 

 whiter in some parts than in others. Microscopic examina- 

 tion in each case discovered the spermatozoa to be present 

 in great numbers, and in full life and activity. 



The spermatophores of D. viridescens are described by 

 Gage ('91) and Jordan ('91) as being composed of three 

 parts: a gelatinous part which serves as a base by which 

 the whole is attached to the bottom of the aquarium ; a 

 spinous portion projecting upwards from this base; and 

 a spherical mass of spermatozoa clinging to the summit of 



