1024 Wisconsin Academy of Sciences, Arts, and Letters. 
paper. The presence of wrinkles on the back of the head, as 
■seen in Daday’s figure and in my figure 1, is evidence that the 
head has been raised. The rostrum is broader and blunter 
than that of Sida but otherwise closely resembles it. The gen¬ 
eral form of the body is oval, especially in older specimens, 
whose dorsal margin is considerably arched. The cervical 
notch is present, but there are no cervical glands. The valves 
are thin and marked only by granulations; the anterior margin 
is concave, with a well marked infero-anterior angle; the ven¬ 
tral margin rounds over into the posterior; the posterior mar¬ 
gin is’ convex below with a concavity at the dorsal part, just 
below the sharp supero-posterior angle. The anterior and 
ventral margins are fringed with long, thin setae set far apart; 
these are especially long at the infero-anterior angle; they ex- 
ttend to the posterior end of the ventral margin; but there is 
no cluster of long spines there as in Latona. 
Appendages: The antennules (plate LXVII, fig. 2) are at¬ 
tached on each side of the rostrum, and are borne on small 
elevations. The basal part is about as long as the ventral mar¬ 
gin of the head; somewhat curved; thicker in the middle than 
at either end. The distal end is truncate and produced on each 
side into minute sharp projections, almost spine-like. There is 
a very long, flexible flagellum, much longer than the basal part, 
covered sparsely with long, fine, straggling hairs. The ol¬ 
factory setae are sessile, or nearly so, on the side of the base 
a little distal to the middle. 
The antenna is large and powerful. The basal joint bears 
two large, short, thorn-like spines, a basal and a distal; it 
has the usual sense seta between the bases of the rami. The 
rami are 2- and 3-jointed; the setae are q 9 th e 
two terminal setae of the dorsal ramus are much longer than 
the others; that on the second joint of the ventral ramus is 
even longer and may measure 1.0 mm. in an animal whose 
total length of about ( 1'.53 mm.; one of the 4 setae on the 
terminal joint is nearly as long, two of the others are much 
less than half as long and are proportionally slender, the 
fourth is still smaller, not as long as the basal joint of the 
