MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
151 
Fig. 2. C. stygia, from Carter Cave.—One of first pair of legs, 2. 
Fig. 3. Asellus communis Say.—Antennule, $, showing the three auditory bristles; 3 a, end of 3, with olfactory rods 
much shorter than in C. stygia; 36, antennule 2, with five auditory bristles; 3c, the same of another indi¬ 
vidual ; 3d, antennule; 3e, antenna, $, from Illinois; 3/, mandible; 3 g, one of the first pair of legs, <?; 3fo 
left cercopod, $ , from Irvington, Indiana. Author del. 
Fig. 4. Asellus, sp. indet., from Gill’s Branch, near Lancaster, Garrard County, Kentucky. Kingsley del. 
Fig. 5. Undetermined; locality unknown. Kingsley del. 
Plate Y. 
Crangonyx vitreus (Cope).— 2,5.2 mm long, enlarged 20 diameters. 
One of the first pair of legs seen trom the outside, enlarged 48 diameters. 
One of the second pair of legs, X48. 
End of the abdomen, side view, x48.— a, telson ; 6, posterior caudal stylet; c, second caudal stylet; d, first 
caudal stylet. 
Crangonyx packardii Smith (details all magnified 48 diameters; 5 to 8, 2> 5.5 mm long; 9 to 11, 2,about 7.5 mm 
long).—Lateral view of the head. 
End of one of the first pair of legs, outside. 
The same of the second pair. 
End of the abdomen, lateral view. 
One of the first pair of legs, outside. 
One of the second pair of legs, outside. 
Antennula and antenna, side view. 
Crangonyx antennatus Pack.—Terminal joints of the antennule, showing the olfactory rods. 
The entire antennule. 13a, basal joint with four auditory set®; 136, fourth joint of the same with its ramus. 
Antenna, with four auditory set®. 
Crangonyx mucronatus Forbes, Illinois.—Antenna, end enlarged; 15a, the same more highly magnified; 156> 
fourth joint still more magnified. (The setul® of the auditory set® are fewer than in C®cidot®a.) 
Crangonyx vitreus Cope (?) .—Basal joint of antennule. (Compare with Fig. 13a.) 
Figs. 1 to 11 drawn by Prof. S. I. Smith. Figs. 12 to 16 drawn by the author. 
Plate YI. 
Fig. 1. Pseudotremia cavernarum (Cope), from Wyandotte Cave, enlarged.—la, head; 16, the same, front view; Id, 
eyes. (Emerton del.) le, eyes of a Wyandotte Cave specimen; If, antenna much enlarged; If, terminal 
joint highly magnified, filled with nerve cells, with numerous tactile set®, and two tactile or olfactory (?) rods 
at the end; lg, under lip or dentomala (compare PI. VIII, fig. If, and explanation); 1 h, labrum, with the 
three central teeth; li, external malella ( mal. e), internal malella (mal. i), and labiella (lab); 1 k, man¬ 
dible of one side; 1 m, the same on the other side; In, six bundles of set® on the free edge of lm ; lo ; eighth 
pair of legs ; lo', one of the legs enlarged; 1 p, a leg of the first pair, next to the head; 1 q, a leg of the last 
pair.; lr, a pair of normal legs; Is, male genital armature; It, the same, different view ; 1 m, end of the body; 
lr, a segment (dorsal view). Author del. 
Fig. 2. P. cavernarum var. cartereysis Pack., enlarged.—2a, head enlarged; 26, side view of another specimen, x6; 
2c, dorsal view of a segment. Emerton del. 
Plate YII. 
Fig. 1. Zygonopus whitei Ryder.—Anterior part of the body without the legs; la, front view of the head; 16, male 
antenna; lc,three segments,enlarged to show the mode of origin of the lateral set®; Id,- le, origin of the 
same with the transversely striated area below the flattened boss from which the set® arise ; If, one of the 
sixth pair of legs of the male, forming claspers; lg, a leg of the seventh pair of the male ; 16, a rudimentary 
leg of the eighth pair (without a claw); 16, rudimentary male genital armature, with a rudimentary claw- 
less leg on one side; li, lm', lamina interior; lm', a bristly seta, very minute (compare PI. VIII, fig. li', ml) ; 
1«, male genital armature, lamina exterior (l. e.) ; lo, the latter enlarged (lp,lq, antenna and labrum, etc., 
of Zygonopus (?) or Trichopetalum). 
Fig. 2. Trichopetalum lunatum Harger.—Head and first three segments; 2a,nearly front view of head; 26,antenna; 
2e, two terminal joints still more magnified; 2d, leg; 2e, a rudimentary leg; 2/, two segments, showing the 
swollen area bearing three set®. 
Fig. 3. Antenn® of Pseudotremia cavernarum. —a, one from Little Wyandotte Cave; 6, from Bradford, and c, from 
Carter (Bat) caves;-3d,3e,3/, not accurately copied by the artist from the author’s camera drawings. 
Fig. 4. Eyes of Pseudotremia cavernarum from different individuals from Bradford Cave! 
Fig. 5. Scoterpes copei Pack.—A pair of legs. 
All the figures drawn by the author with the camera lucida. 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. U. 
Fig. 12. 
Fig. 13. 
Fig. 14. 
Fig. 15. 
Fig. 16. 
