28 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Dendroccelum perccecum Pack. 



Dendroccelum perccecum Pack., Zoology, 142, 1879. 



This interesting form was first observed at different points in Mammoth Cave. It 

 is entirely white, and after repeated examinations of living specimens we could see no 

 eye-specks, the creatures being totally blind. In form it is oval-lanceolate, the head end 

 at times scarcely more pointed than the posterior end, though it is sometimes angular in 

 front, a lobe like process extending out on each side of the head, as observed in other 

 fig. 6. species of the genus. It extrudes a large square-tipped proboscis, the end being orbicu- 

 a cave Pia- lar, and then suddenly withdraws it. Length, 5 mm . 

 drocahtm^e"- This was not uncommonly found under stones in a stream we have called Shaler's 



caecumPaok. j> T00 ^ j a ^g wa ter in Gothic Avenue, in Richardson's Spring, Mammoth Cave, and 

 also in water in Diamond Cave. It is quite active in its habits, moving freely about like an ordinary 

 Dendroccelum lacteum. 



lumbricus sp. 



Earth-worms were not uncommon, though of small size, in Mammoth, Diamond, and other 

 caves ; living especially in the damper situations. 



MOLLUSCA. 



Numerous Helices were found in all the smaller caverns, but as none seemed to be specially 

 bleached or to differ from out-of-door forms, no attention has been given to them. Still, it would 

 be desirable to pay an attentive examination to those living in caves, as there may be found, as 

 have occurred in European caves, some individuals whose eyes have been modified by a cave life. 



CRUSTACEA. 



Cauloxenus stygius Cope. PI. I, figs. 1, la, 16. 



Cauloxenus stygius Cope, Amer. Naturalist, vi., 412, July, 1882, figs. 



This Lernaeau is said by Cope to be a parasite of the biind-fish, and to live attached by the 

 disc to the inner edge of the upper lip. " This position being maintained, it becomes a favorable 

 one for the sustenance of the parasite, which is not a sucker or devourer of its host, but must feed 

 on the substances which are caught by the blind-fish and crushed between its teeth. The frag- 

 ments and juices expressed into the water must suffice for the small wants of this Crustacean." 

 Cope describes and figures the two egg-pouches, but these were not present in the specimen we 

 had for examination. Whether Mr. Cope's genus Cauloxenus really differs from Achtheres or not, 

 we are not prepared to say. " The character," he remarks, " which distinguishes it from its allies 

 is one which especially adapts it for maintaining a firm hold on its host, i. e., the fusion of its jaw- 

 arms into a single stem." In the specimen we figure, however, the arms are much as in Achtheres 

 carpenteri, separate for a part of the way, but not so widely so as in A. carpenteri. The body is 

 short and thick, the head oval-rounded, the u arms" short and thick, and of the same length as the 

 head. The shape of the rest of the body in my specimen is irregular. The reader is, for further 

 details, referred to our camera figures. 



COPEPODA. 

 Canthocamptus cavernarum Pack. PI. I, figs. 2, 2a, 26. 



Canthocamptus cavernarum Pack., Zoology, 297, Fig. 238, 1879. 



Body slender, cylindrical, tapering slowly to the end of the body. Carapace not wider than 

 the segment next behind it, but about three and a half times longer, and equal to the combined 

 length of the succeeding five segments; sixth and seventh segments of the body the longest, the 

 eighth being but little shorter than the seventh. The hinder edge of each segment except the last 



