314 GEOLOGICAL SURVEY OF THE TERRITORIES. 
beaks being rather prominent. Valves uniformly convex. Greatest 
depth, one-eighth of an inch; greatest length, one-quarter of an inch. 
Specimens may occasionally attain to a larger size. Color, deep or ight 
brown, mottled with black. Animal: antenne composed each of twelve 
or thirteen subequal joints. Twenty-four pairs of feet, the six posterior 
ones diminishing gradually away so as to render the last three rudi- 
mentary. The last of all is inserted upon the last caudal segment but 
one. There is a broad subtriangular plate, terminated by two pairs of 
very large spines, curved upwards; the inferior pair being longer and 
slenderer than the upper one. The concave margin of that plate is fur- 
nished with a series of quite small spines. On the uppermost part of 
the post-abdominal plate is inserted a pair of very delicate sword-shaped 
appendages, very difficult to be observed even with a good microscope. 
Along the posterior half of the back there exists a series of sixteen pro- 
cesses, provided upon their upper and posterior sides with about five or 
Six minute-curved spines, the tip of which is bent backwards. The an- 
terior two of these processes are but rudimentary; the most developed 
occupy the middle of the series; the posterior ones again diminish gradu- 
ally as they approximate the post-abdominal plate. 
‘Specimens collected at Cincinnati were sent to the Smithsonian In- 
stitution by Thomas Kite, of that city.” 
Afterward Professor Haldeman makes the following statement, in 
Proc. Acad. Nat. Se., Phil., vii, 34, 1854: 
““T find that the Limnadella described by Mr. Girard, Proceed. Acad., 
vol. vii, page 3, is my Limnadia coriacea, ib., 1, 184, for June, 1842. At 
that time I doubted the propriety of placing it in Iimnadia, chiefly on 
account of the dorsal tubercles meutioned in my description, but I had 
no means of making the necessary comparisons. It was discovered in 
great abundance in a road-side puddle subject to dessication, and al- 
though I removed a number of them to a small pond, I have never met 
with them since.” 
HULIMNADIA ANTILLARUM (Baird). 
LTimnadia antillarum Baird. Proc. Zool. Soc. London, xx, p. 30. Plate XXIII, figs. 1, 
. la, 1b, le. 1852. 
“Carapace valves of a rounded oval shape, and of a transparent whitish 
color; prominent on dorsal margin where the muscular attachment of 
: the body takes place, sloping from thence 
rather suddenly towards anterior extremity, 
where it forms a somewhat blunt point, and 
more gradually to posterior extremity, which, 
as well as ventral margin, is rounded. Anten- 
nules bluntly serrated or crenulated on their 
upper edge, rather shorter than peduncles of 
large antenna, which are stout and not half 
Fic. 15.—EKulimnadia antillarum. the length of the body. They consist of nine 
Enlarged 6 diams. After Baird. articulations, each having one or two long plu- 
mose sete springing from the under edge, and one short stout spine at 
each joint on the upper edge. Caudal lamella of considerable length, 
and beset on under edge with long plumose setz to within a short dis- 
tance of the tip, which is somewhat curved, sharp-pointed, and slightly 
serrated on upper edge. Feet, 18 pairs. 
