PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 345 
the basal joint stout, armed externally at the end with a very long, 
slender spur, about as long as the joint itself; the 2d joint thick, very 
long and bent upward and inward; near the end on the inside is a row 
of small papilla; at the extremity it enlarges into a short, thick hand- 
like portion, the 3d joint, which divides into two long unequally forked 
chitinous appendages. 2d antennee of the female as usual, broad and 
suddenly mucronate at tip. Eleven pairs of feet; much as in Branchi- 
necta and Branchipus: the first endite as usual, but the fringe is rather 
long, as also that of the other endites; the 5th endite square, the 
outer edge hollowed out, the spines on the lower edge few and un- 
usually blunt; the 6th endites more acute than in Branchipus; the 
flabellum large and rounded, fuller than in Branchipus ; the gills rather 
large. The penis consists of two separate very long curved filiform 
processes. Ovisac of the female long and slender, much as in Brancht- 
necta. Caudal appendages longer and broader than in Branchipus. 
This genus differs from Branchipus in the want of frontal appendages, 
and may be easily identified by the long 3-jointed twisted and elbowed 
claspers, and by the two long slender filamental processes forming the 
male genital armature. Judging by the form of the 2d antenne, par- 
ticularly the 1st joint, and by the absence of any frontal appendages, 
and especially the form of the ovisac, Streptocephalus appears to be a 
modified Branchinecta, and to have been differentiated from that genus 
rather than from Branchipus; in fact we may, I think, regard Branchi- 
necta as the more generalized, ancestral type of the family. 
Synopsis of the species. 
Male claspers larger and slenderer at tip than in S. similis ...S. teranus. 
Male claspers shorter than in S. tevwanus......-..---- see. eee: S. sealir. - 
Male claspers shorter and broader at base than in S. tew- 
CRUST, ise he) Beals WA Si Na Us gta kA Shy Sha Ye SP aes Met ae S. floridanus. 
STREPTOCEPHALUS TEXANUS Packard. 
Plate XII, figs. 1-7. 
Streptocephalus texanus Pack., Amer. Journ. Se. August, 1871. 
Streptocephalus watsonii Packard, Hayden’s Annual Report of the U. 8. Geol. & Geogr. 
Survey of the Territories for 1873, p. 622, Pl. IV, fig. 13. 
Male.—Front of the head with a small median lobe which projects 
downward between the bases of the second antenne, and is flattened, 
Fic. 20. Streptocephalus texanus, enlarged. 
broad at the end, but not lobed, there being but a very faint median 
sinus. The subconical upper surface of the head bearing the oblong 
ocellus near the front edge is truncated-conical, being a little longer than 
broad. 1st antenne long and slender, twice as long as the eyestalk, 
