72 A REVISION OF THE ASTAC1D.E. 



the peculiar mode of life of this species would serve to identify it to those 

 familiar with its habits. 



Specimens from the West are larger than the Eastern examples, and Lave 

 a broader antenna] scale. In many of the Eastern specimens, moreover, the 

 bounding lines of the areola are not so closely approximated as in the West- 

 ern form, a very narrow linear space being left in the centre. Specimens 

 from New Orleans. La., have a narrower rostrum with the sides nearly par- 

 allel, a narrower epistoma. and metacarapace longer in proportion to the 

 procarapace. This form I have called C. Diogeiw*. var. Ludoviciana. 



A male specimen (M. C. Z., No. 3G09) from Detroit, Mich., collected by 

 Mr. II. G. Hubbard from a burrow in blue clay in company with C. (n-cjiUi- 

 cola, differs from the common Western form in having a narrower, more taper- 

 ing rostrum, less clearly foveolate at its base, a longer apical spine to the 

 antennal scale, and the post-orbital ridge more interrupted anteriorly to the 

 posterior callosity, which is in the form of a prominent tubercle. The fingers 

 are shorter, giving the chela a more conical shape. The terminal segment 

 of the telson is more oval behind, and the sides of the areola are not so 

 closely approximated. A female specimen (M. C. Z.. No. o45S) from the 

 neighborhood of Mammoth Cave agrees very nearly with this male from 

 Detroit. The body is more attenuated than in the ordinary form, in this re- 

 sembling ('. gracilis. The other specimens which I have seen from Kentucky 

 are too small to determine with certainty. 



I have seen no specimens of C. Diogenes from Tennessee, although it 

 probably inhabits that State, judging from the mud " chimneys," similar to 

 those built by this species, collected by Mr. Edward Palmer. 



The female noticed by Ilagen (p. 82), considered by him to be an 

 abnormal and deformed specimen of 0. Diogenes, is C. gracilis Bundy. 



C. Diogenes is pre-eminently a burrowing species, being found in mead- 

 ows and clay bottoms, often at a great distance from any permanent stream. 

 Girard has given an account of their burrows and the mud "chimneys" 

 which they build over them. His observations were made in the neighbor- 

 hood of the city of Washington. ''The holes, as they appear at the sur- 

 face of the ground, are nearly circular, from seven tenths of an inch to 

 one inch and one inch and a half in diameter. The depth of the burrows 

 varies according to the locations; this we generally found to be from six- 

 teen inches to two feet, and sometimes to three feet and more. The con- 

 struction of the burrow itself is often exceedingly simple : from the surface 



