22 
Br. Baird on the genus Cypridina^ 
derable difficulty I succeeded in dissecting it. For the accom- 
panying sketches of this species I am indebted to the pencil of 
Mr. Charles Ager. 
The eyes I did not succeed in making out. The first pair of 
antennse (PI. VI. fig. 3) are large and pediform : they consist 
each of four articulations. The first or basilar joint is stout and 
of a considerable size ; the second is nearly equally large ; the 
third is short, about half the size, and the last is more slender and 
terminated by several strong setae. From the junction of the 
third and fourth joints issues a bundle of long slender setae as in 
Cypris, and the second articulation is beset on both upper and 
under edge with numerous strong setae also. The organ which he 
calls the natatory foot (fig. 4) is however a very remarkable one : it 
consists of a very large, fleshy, round basilar joint, from which 
issue two branches separate from each other and differing in size 
and structure. The superior is much the larger of the two, and 
consists of one long and stout joint and six short ones, from the 
base of each of which issues a long hair. The inferior branch is 
much smaller and consists of two nearly equal joints, the lower ter- 
minating in two short claws. According to the figure given by 
M. Edwards, this pair of feet consists of only one branch instead 
of two. The mandible I did not succeed in seeing ; but the first 
pair of jaws appeared to be very like that organ as represented 
by M. Edwards. The second pair of antennae presented the ap- 
pearance given in fig. 5, but the parts were too rigid to enable me 
to describe it distinctly. On the posterior portion of the animal 
there was another organ, which is described by M. Edwards in the 
Cypridina as a slender, cylindrical, filiform and twisted body 
which supports the ova. In this species it appeared a cylindrical 
body (fig. 6) composed of a very great number of small joints, of 
a twisted form, and giving off from each side several pretty long 
setse which appear numerously jointed also and furnished at their 
extremities with sharp spines. It resembles more the same organ 
as described in the Asterope by Philippi than that in the Cypri- 
dina of Edwards. The abdomen is terminated by a double caudal 
plate (PI. VI. fig. 7), broad, flat, and armed with nine spines ; six 
of which are very strong and serrated on their under edge. The 
first is the longest and they gradually become shorter as they 
descend, the three last being much smaller than the others, not 
serrated on their under edges, but furnished with a tuft of short 
seta3 at their extremities. This caudal plate appears to be a simple 
continuance of the abdomen, and not articulated with it as in the 
tail of Cypridina figured by M. Edwards, and in this particular 
resembles much more nearly that organ as represented by Phi- 
lippi in his Asterope. 
Sp. 2nd. Ciypridina Adamsi. PI. VII. fig. I. Shell of the size 
