MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
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Fig. 6. Anophthalmus larva (presumably of A. tellkampfii) ; Emerton del.—6a, antenna; 66, maxilla; 6c, labium and 
labial palpi; 6d, labrum. 
Fig. 7. Pupa, presumably of A. tellkampfii. Emerton del. 
Fig. 8. Adelops hirtus Tellkf. Emerton del. 
Fig. 9. Adelops hirtus Tellkf. Larva. Emerton del.—9a, antenna. 
Fig. 10. Batrisus spretus. Emerton del. * 
Fig. 11. Quedius fulgidus. Emerton del. 
Figs. 12 and 13. Staphylinid beetles, not identified, from caves. Emerton del. 
Fig. 14. An unknown eyeless Coleopterons larva from Bat Cave. Emerton del. 
Fig. 15. A stapbylinid larva, not identified, from cave. Emerton del. 
Fig. 16. Blastoderm cells on surface of egg of tbe cave spider, ( AnthroMa mammouthia). Author del. 
Plate XXI. 
f 
Fig. 1. Brain and eyes of an undetermined Cambarus with normal eyes; c, cornea; op. n, optic nerve; ant 1 , first an¬ 
tennal nerve ; ant 2 , nerve of second pair of antenn®. 
Fig. 2. Brain and rudimentary eyes of Orconectes pellucidus, lettering as in Fig. 1. 
Fig. 3. Section of eye of Orconectes hamulatus Cope and Packard; op. gang., optic ganglion ; g. c., ganglion cells; hy., 
hypodermis; mus., adductor muscle; con. c., connective tissue cells. 
Fig. 3a. Section of the same, near the middle of the eye; op. n., optic nerve; a, a mass of ganglion-cells extending 
, to the end of the cornea. 
Fig. 36. Section very near the preceding; 3c, connective tissue cells from the side of the optic ganglion; 3d, ganglion 
cells, with the walls nearly effaced; x, a large one surrounded by those of ordinary size; 3e, a few con¬ 
nective tissue cells in the place occupied by the rods and cones of the normal eye; 3/, hypodermis at end 
of the eye, in place of the cones of the normal eye, the cell walls mostly obsolete ; 3 g, nuclei. 
Fig. 4. Auditory set® from within the ear from an undetermined Cambarus, with normal eyes; 4', one of the same 
more highly magnified. 
Fig. 5. Set® from 0. pellucidus from Indiana; situated around the entrance to the ear; 5a, auditory set® from the 
auditory sac of the same. 
Fig. 6. Auditory set® from the ear of Orconectes hamulatus; 6a, the same enlarged. 
All the figures drawn by the author. 
Plate XXII. 
Fig. 1. Chlcenius pensylvanicus. —Head dissected to show the brain, with optic ganglia (o. g.) and optic nerves and 
eyes; pc. 1 ., procerebral lobes, or central part of the brain. 
Fig. 2. Anophthalmus tellkampfii. Head, showing the central portion or brain proper, the optic ganglion and optic 
nerves with the eyes being totally abolished. 
Fig. 3. Anophthalmus tellkampfii. Longitudinal or sagittal section of the head; pel, supracesophageal ganglion; s. a?, 
subcesophageal ganglion ; /. g., frontal ganglion ; mx. n., nerve to the maxill®; mx. m.., maxillary muscles ; 
mx', base of maxill®; l. n., nerve to the lingua (1.); m., mouth; md ., mandible; Ibr., labrum; com., com¬ 
missure. 
Fig. 3a. The same; longitudinal section on one side of the preceding; sg', sg 2 , salivary glands; l, lingua; pv, proven- 
triculus; st, stomach. 
Fig. 4 to 4 e, horizontal sections through the brain of Anophthalmus tellkampfii; if, vertical section. For the sections 
see PI. XXIII, fig. 2 to 2c. 
Fig. 5. Orconectes pellucidus, from acave in Indiana. Olfactory rods on the terminal three joints of the outer flagellum. 
Fig. 6. Set® from near opening to the ears of 0. pellucidus, from cave in Indiana. 
Fig. 7. Olfactory rods of Orconectes pellucidus ; 6a, 66, 6c, the same magnified, with nerve-cells in the base. 
All the figures drawn by the author with the camera lucida. 
Plate XXIII. 
Fig. 1. Asellus communis. Op. g., optic ganglion; op. n., optic nerve; e., eye; rec., retinal cells; la, portion of the brain, 
with the optic ganglion and optic nerve and eye of the same enlarged ; 16, section through th? head and brain 
of Gcecidotcea stygia, showing the,entire absence of the optic ganglion and optic nerve, and the rudimentary 
eye; ret. , rudimentary retina; lc, sections through the rudimentary eye, composed of two facets; Id to 1 d iT , 
sections through the eye of the same ; at Id a single facet; at Id" three; at ld iT a single lens surrounded 
by the retina. 
Fig. 2 to 2c, vertical sections through the head and brain of Anophthalmus tellkampfii. 
Fig. 3, 3a, 36, 3c, 3d, sections through the head and eyes of Adelops hirtus, showing the entire absence of optic ganglia 
and optic nerves; at 3a' the eye is seen with rudiments of three lenses surrounded by the rudimentary pig¬ 
ment. 
All the figures drawn by the author with the camera. 
