418 MKMOIKS OF THE CARNEGIE MUSEUM 



h. Shape of the burrows. (See PI. XL, Figs. 8 and 9, PI. XIJ.) 



The burrows of these species (and also of C. bartoni) are to a certain degree alike, 

 although they are very vai'iable in depth and shape, so that there is very little uni- 

 formity. Only a few features are common to them. From the more or less dry 

 surface they go down to the groundwater, where there is generally a kind of a pocket 

 or widened chamber (PI. XLI, lugs. 5 and 6). The width of the hole corresponds 

 to the size of its inhabitants. It seems that one and the same individual perma- 

 nently uses the .same hole, although one and the same hole may be oceujiied by dif- 

 ferent individuals in succession, for an old abandoned hole may be occupied l)y a 

 young specimen. This happens chiefly in localities where the holes are much 

 crowded. There are places where the ground is fairly honeycombed with them," and 

 under such conditions a new hole may interfere with an old one, when a young 

 specimen after attaining the proper size begins to Ijuild its own burrow, as it invari- 

 ably does. If the old hole is abandoned the young specimen may take advantage 

 of it, while in the alternative case, a fight ensues which ends in the expulsion or de- 

 struction of the weaker. 



Each hole is always occupied by o/u' individual only, with two exceptions. The 

 first is the case of mating couples, when one adult male of the fir.st form and one 

 female are found in one and the same hole. The second is when the young of a 

 certain size are associated with the mother in the hole of the latter. 



The holes have all manner of shapes (see PI. XL, and PI. XLI), They may con- 

 sist of a single shaft only, or may be more complex, branching oft' in various direc- 

 tions, and may have more than one opening at the surface. The chaml)er may be 

 well marked or indistinct, and there may be several chambers. The chambers may 

 be simple widenings of the hole, or may form side pockets. The direction of the 

 descending shaft is rarely more or less vertical, and if vertical in the upper part, it 

 generally soon assumes a slanting direction, and sometimes it is irregularly spiral. 

 Shorter or longer branches may go off' at the sides, and these may end blindly or 

 may ascend to the surface. At the bottom side-branches may be absent, or may be 

 developed to a considerable extent, running either horizontally or vertically. On 

 steep hillsides, or along the banks of ditches, the general direction of the burrows is 

 very often horizontal, the outward opening being lateral (PI. XLI, Figs. 2, 'A, 7). 



The depth of the holes depends on the distance of the level of the groundwater 



'5 1 have seen this on the largest scale in the case of C. cnroliniis in the valley of Upper Decker's Creek near Reedsville, 

 Preston County, W. Va. The whole valley, for two or three miles, offers favorable conditions for this species, and 

 thousands of chimneys ujay be seen everywhere, coming up even between the railroad ties of the Morgantown & King 

 wood Railroad. 



