342 GEOLOGICAL SURVEY OF THE TERRITORIES. 
BRANCHIPUS VERNALIS Verrill. 
Plates XI, figs. 2-6; XXII, figs. 3-6. 
Branchipus stagnalis Gould, Invertebrata of Massachusetts, 339, 1841. 
Branchipus vernalis Verrill, Amer. Journ. Sc., XLVIIT, 251, Sept., 1869. 
Eubranchipus vernalis Verrill, Proc. Amer. Assoc. Adv. Se., July, 1870. 
Body stout, pale flesh-colored with reddish tints, head large; claspers 
with the basal joint very stout, slightly curved, nearly one-half as thick 
as long; retractile, drawing in ’ with it the base of the 2d joint; 2d joint 
chitinous, rigid, with a ‘long obtuse spur on the inner side at ‘the base, 
which is directed inwards at right angles; beyond this spur the joint 
in transverse section triangular, the edges very prominent; the inner 
edge of the joint is hollowed out at the base, while the extremity is bent 
outward somewhat like the foot of a sock before it is worn. The inter- 
antennal or frontal appendages are broad, triangular, flat (from above 
downward), nearly twice as long as broad, acutely pointed; with the 
edge finely serrated, the teeth, when highly magnified, being separate 
at base, and bottle-shaped, with one, and sometimes two, rarely three, 
‘‘ necks” or ‘ points” (Pl. X XI, fig. 5, 5a). The external organ of re- 
production (penis) is stout, massive, not deeply cleft in the middle, 
while the cirrus (Pl. X XII, fig. 3, ¢) is minute, long, and filiform. 
The body of the female is as stout and of the same size as in the male; 
the ovisac is not so long as broad, pink, with a prominent, full ‘‘ neck,” 
with a transverse narrow opening "tor the exit of theeggs; the lower lip 
of the opening is smaller than the upper lip. 
Male.—Totallength of body, 23"; of 2dantenne, $="; 2d joint of same, 
4.5°"; of penis, 3.5" ; caudal appendages, 4mm. 
Female.—Total length, 23™"; length of ovisac, 3-4™"; of caudal ap- 
pendages, 47”. 
This species ranges from Salem, Mass., through Rhode Island to New 
. Haven, and southward to Philadelphia (March 27, Mr. W. P. Seal) and 
westward to Southern Ohio (Wapakoneta, Ohio, Wm. Kayser), aud In- 
diana, (received from Irvington, Ind., Mr. O. P. Hay, Amer. Nat. 1882, 
242). In Southern New England it is found from the last of November 
until the first week in May, but has not yet been found during the sum- 
mer from the middle of May until the middle of November, as will be 
seen by the following record of localities and dates of capture: Salem, 
Mass., April 19, 1859 (RB. H. Wheatland, Essex Institute); April 12, 1876, 
a few half-grown ones (Packard); Danvers, Mass., Nov. 25, 1578, Decem- 
ber and Jan. 10 (John Sears); Brookline, Mass., March 30, 1878 (ia 
Henshaw); Pawtucket, R. L, March 18, 1880 (H. H. Davison); New- 
port, hk. ie Feb 15, 1877 (Mr. Powell, Mus. Comp. Zool.); New Haven 
(Dana, Haton & Verrill); At Seekonk, Mass., they occurred abun- 
dantly May 2, in a large pond which completely dried up in summer 
(H. C. Bumpus) ; when it visited the pond in company with Mr. Bumpus, 
May 13, none were to be found. It seems from this quite evident that 
- the animal probably dies off at the approach of warm weather and does 
not reappear until after cool weather sets in late in the autumn, being 
represented in the summer by the eggs alone; and thus the appearance 
and disappearance of this Phyllopod is apparently determined mainly 
by the temperature. 
In life the body is of a pale flesh color, the tips of the penis deep red- 
dish-brown, from thence a narrow line widening to the posterior half of 
the abdomen. The white sete on the caudal appendages and the white 
tips of the endites contrast with the deep reddish-brown of the rest of 
