164 MR. NEWPORT ON THE OCELLI 
Further I may mention, with regard to the question concerning the eye-spots in the 
Arachnida, that I have found by dissection in the Scorpionide, not only that these are 
always situated in the exact place of eyes in other species, but also that they always 
receive a nervous filament from the same optie nerve which supplies the distinctly recog- 
nised organs of vision. 
These facts, I trust, will be sufficient to show the general correctness of the description 
which I originally gave of the male Anthophorabia, that it is distinguished by the pos- 
session of ocelli, both at the sides of the head and on the vertex. 
May 9, 1853.—To the foregoing remarks I may add a word on the condition of the eyes 
in the so-called blind Crustaceans from the caves of Kentucky. Distinet eyes exist both 
in Triura cavernicola and in Astacus pellucidus, Tellk. In Triura the eyes have very 
short pedicles, and are almost close together. In Astacus (fig. 11) they are partially 
concealed beneath the front of the head (4); their pedicles are conical, much shorter than 
in other species of the genus, and possess but little power of motion. The eye itself 
(fig. 12 and 134), although existing as a distinct structure, is destitute of a pigmentary 
choroid, in which respect it may be compared to the eye of the Albino. But the hardened 
tegument which clothes the entire organ is thinnest-and most transparent in that part 
which forms the cornea (3) in other crustaceans; so that, although the eye may be un- 
fitted for distinguishing form, the creature may yet possess the faculty of perceiving the 
small amount of actinic rays of light which penetrate into its subterranean abode. The . 
cornea also exhibits an appearance of being divided into a few imperfect corneales at the 
apex of the organ (fig. 14), and the structure behind these into chambers, to which a small 
but distinct optic nerve is given (fig. 13 d d). 
Probably other Articulata, which have been supposed to be entirely destitute of eyes, 
which covers the place of the supposed lost organ thinner and more permeable to light 
to infer that this may prove to be the fact in all, 
from the already acknowledged susceptibility of some of the supposed eyeless insects to 
the presence of light; and also from the cireumstance that in one of the Coleoptera, and . 
in an Orthopterous insect, of the dark caves, Adelops hirtus and Phalangopsis ?, the 
eye, as in others of the tribe, is distinctly indicated, as already shown by Tellkampf and 
by Thomson*. Hence we may fairly assume that the supposed eyeless Articulata differ 
from others of their class rather in the degree, than in the entire absence, of power of 
appreciating light. 
* Annals and Magazine of Natural History, vol. xii. p. 112, No. 82. Feb. 1844. 
