420 GEOLOGICAL SURVEY OF THE TERRITORIES. 
VI. MISCELLANEOUS NOTES ON THE REPRODUCTIVL HAB- 
ITS OF BRANCHIOPODID Zi! 
By CARL F. GIssLER, Ph. D. 
I. EUBRANCHIPUS VERNALIS Verrill.? 
Among the very large individuals gathered during the past winter 
(1879~80), I found a male and female, each with but one right clasper. 
Several experiments on Eubranchipus showed that the least artificially 
applied lesion of the claspers proved to be fatal to them, and so I am 
inclined to see in the above mentioned two specimens simply a mal- 
formation acquired through some unknown cause at an early larval 
stage. Where the other claspers ought to be the integument is perfectly 
smooth and rounded. During eleven days I could never see the mal- 
formed male in copulation, although I always noticed him pursuing the 
females. He was frequently seen to be touched by other normal males, 
especially when they approached his left side from behind, on account 
of the missing left clasper, and also probably on account of the exces- 
sively swollen genital segment, taking it for a female bag. This singu- 
lar individual presented altogether much oddity in its behavior. Un- 
like the others, it often swam suddenly through the aquarium in a bee- 
line, frequently resting on its back at the bottom of the jar for 10 or 12 
minutes, slowly moving its branchipeds. Perfect sammersaults and 
other curious motions were often noticed. 
The malformed.female did not present any odd movements; I kept it 
for several days alive and could see no other anomaly about it. The 
largest females usually preferred the bottom of the aquarium as a 
protection against the ever-attacking males. In old females I often no- 
ticed a laceration of the furca® (sometimes entirely gnawed off), caused 
by insect-larve crawling about the bottom. They bear a lacerated 
furca well for a long time, as the furca merely consists of chitin and. 
bristled integument. 
The larger ponds were found already in January to swarm with Lym- 
netis gouldit Baird, a great number of a species of Daphnia, many Cy- 
pridine, Cyclopide, and Calanide. 
If the months of November and December are mild, as has been the 
case during the past three years, there occur in January adults 14 inches 
long, as well as larve of only a few millimeters in length. Three years 
ago they disappeared in the beginning of May, year before last in April, 
last year in March, and this year (1881) i in the middle of April. A sudden 
change in temperature, warm or cold, will cause them to disappear for 
two or three days, when, atter another change, they suddenly reappear 
diminished in number and in company with another young generation. 
The female sexual organs of the red Hubranchipus vernalis are less 
complicated than those of its pale races, and I have occasionally alluded 
to them in describing those of the latter: 
Copulation in the ‘red Eubr anchipus lasts but a moment, and on this 
account I was unable to closely observe the same. 
SEXUAL ORGANS. (Plate XXII.) 
(1.) Male organs.—The posterior (lower) tapering end of the testicle is 
fastened by a very fine hyaline thread to the wall near the eighth post- 
1 This is in part a continuation of a paper entitled ‘‘ Evidences of the effect of chem- 
ico-physical influences in the evolution of Branchiopod Crustaceans,” read before the 
29th meeting of the Amer. Assoc. Ady. Sc. held at Boston, Aug. 1880. 
2 Observations on Phyllopod Crustacea, . etc., by Prof. AE. Verrill, 1869. 
3 The red Eubranchipus has a white furea, the pale races have a red furca. 
