PACKARD.] REPRODUCTIVE HABITS OF BRANCHIPODIDA. 425 
and deseribed by Dr. R. Buchholz, in his “ Brancbhipus Grubii von Dy- 
bowsky,” Tatel III, fig. 6, with the exception that the blind append- 
age of the descending testis is missing. 
The smallest larval stage I obtained from the Glendale pond measured 
3™™ in length, but when mounted in glycerine jelly I could not tell 
whether it was a Chirocephalus or an Eubranchipus larva, as the frontal 
tentacles were not exposed. The 
same thing occurred in three other 
larger larvee. One larva of 43mm in 
length showed the appendage as illus- 
trated by Fig. 48. The inner basal 
clasper-hook just budded, is turned 
downward, the anterior, upper sur- 
face of the second antennz and the 
frontal tentacle is seen. Another 
larva scarcely larger ’ second antenne Fie. 49.—C. holmani, second antenna with 
in about the same stage of develop- frontal tentacle, from above. 
ment, exhibits the frontal tentacle as illustrated by fig. 49. It appears, 
and I judge trom twenty-six mounted heads (in glycerine jelly) that the 
growth of the frontal tentacles of our Chirocephalus is very rapid, its en- 
tire length being probably attained between two exuviations. 
IIL.—LARVAL STAGES OF APUS LUCASANUS Packard ESTHERIA COM- 
PLEXIMANUS Pack. AND STREPTOCEPHALUS TEXANUS Packard 
(Plates XXXIV, XXXV). 
From dry mud received from Dr. L. Watson, of Ellis, Kans., I hatched 
numerous specimens of larve of both Str eptocephalus fexanus Pack, and 
Estheria compleximanus Pack. but only three specimens of Apus lucas- 
anus Pack. The mixture of mud and fresh water was kept at a tempe- 
rature of about 75° to 80° F. during the summer months, and in nearly 
every instance, after the third or fourth day, I could, with the naked 
eye, observe some small larve actively swimming about in the aqua- 
rium. The larve of Streptocephalus, as well as those of HL. compleximanus, 
look at first like little white birds, and Prevost, in Jurine’s ‘“ Histoire 
des Mouocles,” in 1820, has compared the larvae of Chirocephalus in a 
similar manner. 
I have often obtained from one and the same lump of mud both the 
very small Nauplii of Estheria compleximanus and the Streptocephalus 
texanus but, strange as it appears, when the larvee of the two genera - 
were thus together, only those of the former (Hstheria) survived, but 
those of the latter rapidly died off. In the single instance, when three 
Apus larve of several millimeters length were found at the bottom, they 
were also the only occupants of the jar. F. Spangenberg has drawn at- 
tention to this fact on page 61 of his paper on Branchipus stagnalis. He 
says that a single larva of Apus cancriformis kills in a few days a 
number of Branchipus larve. How one kills the other I could not ob- 
serve, but have either raised Streptocephalus alone or Estheria or 
Apus alone. It is very likely that the secretion of the antennal gland, 
which is present in all members of this family, whose outlet is under the 
base of the second antenne, is antagonistic to other species. The prin- 
cipal function of the gland is believed to be for lubrication, to assist the 
constantly-moving second antenne. Its early appearance in the larva, 
its comparatively large development, together with its distinct orifice, 
may give support to my opinion. 
F. Brauer, C. Claus, and FI. Spangenberg agree that the new-born 
Apus sinks to the bottom, and gradually, with sluggish motions, rises 
