314 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



beaks being rather prominent. Yalves 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 light 

 brown, mottled with black. Animal : antennte 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 beiug 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 diihcult to be observed even with a good microscope. 

 Along the posterior half of the back there exists a series of sixteen pro- 

 cesses, provided ui)on 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. ^STat. Sc, Phil., vii, 34, 1854: 



"I find that the Limnadella described by Mr. Girard, Proceed. Acad., 

 vol. vii, page 3, is my Limnadia coriacea, ib.j 1, 184, for June, 1842, At 

 that ti]ne I doubted the propriety of placing it in Limnadia, chiefly on 

 account of the dorsal tubercles mentioned 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 pontl, I have never met 

 with them since." 



EULIMNADIA ANTILLARUM (Baird). 



Limnadia anlillarum Baird. Proc. Zool. Soc. London, xx, p. 30. Plate XXIII, figs. 1, 



la, lb, Ic. 1«52. 



" Carapace valves of a rounded oval shape, and of a transparent whitish 



color; prominent on dorsal margin where the muscular attachment of 



^•T,,,,^ the body takes jilace, 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 



ux)per edge, rather shorter than peduncles of 



\ V - large antenna?, which are stout and not half 



Tig. \r,.—Eiiiimnadia antiiiarwm. the length of thc body. Thcj cousist of nine 

 Enlarged G diams. After Baird. articulatious, cach haviug ouc Or two loug plu- 

 mose setce springing from the under edge, and one short stout spine at 

 each joint on the upper edge. Caudal lamellee of considerable length, 

 and beset on under edge with long plumose setoe to within a short dis- 

 tance of the tip, which is somewhat curved, sharp -pointed, and slightly 

 serrated on upper edge. Peet, 18 pairs. 



