MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 61 



dites, composed of the usual lamina externa and lamina interna, which are variously spined and denticulated at their 

 extremities, one supplementary spine being minutely and densely spinulated. 



The genus was characterized by Cope thus: "Annuli with two pores on each side the median line." As already 

 remarked, the so-called pores appear to be simply the lateral tubercles, giviug rise posteriorly to minute setae, which 

 are difficult to detect with a half-inch objective. 



The genus differs from Lysiopetalum in the slenderer, longer antenua3, the rudimentary eyes, the more swollen 

 and prominent lateral bosses or shoulders of the segments, while the body has about half as many segments as in 

 Lysiopetalum, and is much shorter aud more fusiform. The generic characters are very marked, though the species 

 is clearly enough derived from the common out-of-door Lysiopetalum lactarium. 



Pseudotremia cavernarum Cope. Plate VI, figs. 1, la-It* ; 2, 2a-2c. 



Pseudotremia cavemarmn Cope, Proc. Amer. Phil. Soc, xi, No. 82, 179, 1869. 



Pseudotremia oavernarum Cope, Trans. Amer. Eut. Soc, iii, 07, May, 1870. 



Pseudotremia cavernarum Packard, Amer. Naturalist, v, 749, December, 1871. 



Spirostrephon cavernarum Cope, Amer. Naturalist, vi, 414, July, 1872. 



Spirostrephon (Pseudotremia) cavernarum Harger, Amer. Journ. Sci. and Arts, iv, 118, 119, August, 1872. 



Pseudotremia cavernarum Ryder, Proc. U. S. Nat. Mus., iii, 526, February 16, 1881. 



Eyes black, conspicuous, forming a somewhat irregular, narrow triangular patch, with from twelve to lifteen 

 facets. Antenna? unusually long and slender, the joints pilose ; joints 3 and 5 of the same length, or 3 a little longer ; 

 joints 2 and 6 of equal length ; joint 7 elongate, pear-shaped, pilose, the extremity truncated, with two or three 

 sense-seta? uot so long as the end of the joint is thick. 



The first scutum next to the head is scutellate iu shape, rounded on the front edge, somewhat produced anteriorly 

 in the middle; the margin behind slightly sinuous; it is about two-thirds as long as broad. The second scutum is a 

 little wider than the first, the third somewhat wider, while the fourth is much wider; dorsal face of first scutum 

 smooth ; the posterior part of the second scutum a little swollen ; that of the third more so ; that of fourth scutum 

 swollen and ridged much as in fifth and succeeding scuta. Scuta 5 to 20 are swollen high up on the sides into a 

 shoulder, giving a quadrilateral instead of a circular outline to the segment, bulging out more subdorsally than 

 below; the swelling has six longitudinal ridges, while the posterior swollen end of the scuta above, especially on the 

 posterior half of the body, is coarsely tubercnlated, the tubercles being rounded rather than flat and unequal in 

 size. No well-marked setiferous tubercles on the side from the middle of the body to the head ; but on the last six 

 segments there are on each shoulder or scutal swelling two minute rudimentary swellings or tubercles; but in my 

 specimens I can see no setae except on the two terminal segments of the body iu male and female, where, on the end 

 of the last scuta, there is a seta arising from a basal movable joint ; there are three pairs on the lateral anal plates 

 (thirtieth segment). Length, 18 mm ; thickness of the body, 1.5 mm . 



The young when about half grown are white, the back of the antenna? and anterior segments having a very 

 slight dusky tinge. In numerous mature specimens from the Senate Chamber, Wyandotte Cave, 3 miles in, the body 

 is white, with a slight flesh-colored tint. In numerous (150) specimens from this locality the head and dorsal side 

 of the anterior segments are slightly dusky ; the antenna? are also usually slightly dusky, except the two terminal 

 joints, which are white. 



There is thus seen to be a slight amount of variation in color in specimens collected at the same date in the 

 same chamber in Wyandotte Cave. 



Among the 150 specimens taken at one time and place from Wyandotte Cave (Senate Chamber) and individually 

 examined I could see none without black eyes, the pigment being well developed. There was a fair proportion of 

 males. 



Four specimens which I collected in Little Wyandotte Cave were of exactly the same size as those from Great 

 Wyandotte Cave; they were white-tinged, dusky on the head and forepart of the body, the eyes are black, and the 

 eye-patch of the same size and shape, while the antenna? are the same. 



Six specimens from Bradford Cave, Indiana (which is a small grotto formed by a vertical fissure iu the rock, and 

 only 300 to 400 yards deep), showed more variation than those from the two Wyandotte caves. They are of the same 

 size and form, but slightly longer and a little slenderer, especially joints 3 and 5; joint 7 is decidedly longer than in 

 any others ; whiter, more bleached. The antenna? are much whiter than iu those from the Wyandotte caves, and the 

 head and body are paler, more bleached out, than in most of the Wyandotte rpecimens. The eyes vary more than iu 

 the Wyandotte examples, one having but twelve facets, another fourteen, and another fifteen, with a few minute 

 rudimentary facets between the others. It thus appears that (he body is most bleached and the eyes the most rudi- 

 mentary in the Bradford Cave, the smallest and most accessible, and in which, cousequently, there is the most varia- 

 tion in surroundings, temperature, access of light, and changed condition of the air. Under such circumstances as 

 these we should naturally expect the most variation. 



Professor Cope's types were first found by him in Erhart's Cave, Montgomery county, and Spencer Run and Big 

 Stony Creek caves, in Giles county, Virginia; also in Lost Creek Cave, on the Holston River,. in Grainger county, 

 Tennessee, and in other limestone caves of the valley of the Tennessee. Professor Cope afterwards (A.mer. Natural- 

 ist, vi, 14) discovered this species in Wyandotte Cave, remarking: "The species is quite distinct from that of the 

 Mammoth Cave, and is the one I described some years ago from caves in Virginia and Tennessee," 



