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ME MOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
91 
Class PYCNOGONIDA. 
The deep-sea species are either eyeless or with rudimentary eyes. 
Class CRUSTACEA. 
Order Cirripedia. 
Rhizoeephala. All are eyeless, while the barnacles have rudimentary eyes. 
Order Branchiopoda. 
Bradya limicola Herrick. In mud in ditches, near Mobile, Ala. 
Bathynella natans Vejovsky. Eyeless. Wells in Prague. 
Canthocamptus cryptorum Brady. “ Eyes wanting; ” (?) none represented in the figure. In a coal mine, New¬ 
castle, England. 
Siphonosiomata. All the members of this group of ectoparasites are eyeless. 
Cypris eremita Ye j. White and eyeless. Wells in Prague. 
For preparing the following list of higher Crustacea, mostly deep-sea forms, I am indebted to 
Prof. S. I. Smith, of Yale University. 
Order Amphipoda. 
Anonyx calcaratus G. O. Sars. “No distinct eyes.” North Atlantic, 600 to 1,200 fathoms. 
A. typhlops G. 0. Sars. “No eyes.” North Atlantic, 1,700 fathoms. 
Trypliosa pusilla G. O. Sars. “No eyes.” North Atlantic, 1,000 fathoms. 
Acidostoma laticorne G. O. Sars. “No eyes.” North Atlantic, 200 fathoms. 
Harpinia abyssi G. O. Sars. “ No eyes.” North Atlantic, 350 to 2,200 fathoms. 
H. carinata G. O. Sars. “No eyes.” North Atlantic, 600 to 778 fathoms. 
H. mucronata G. O. Sars. “ No eyes.” North Atlantic, 150 to 600 fathoms. 
H. sonata G. O. Sars. “ No eyes.” North Atlantic, 100 fathoms. 
Urothor abbreviata G. O. Sars. “No eyes.” North Atlantic, 600 fathoms. 
(Ediceros macrocheir G. O. Sars. “ No eyes.” North Atlantic, 1,000 fathoms. 
Mcera tenera G. O. Sars. “No eyes.” North Atlantic, 417 fathoms. 
Melitapallida G. O. Sars. “No eyes.” North Atlantic, 1,300 fathoms. 
Bruzelia serrata G. O. Sars. “No eyes.” North Atlantic, 350 fathoms. 
Danaia abyssicola G. O. Sars. “No eyes.” North Atlantic, 447 fathoms. 
Lilljeborgia cequicornis G. O. Sars. “ No distinct eyes.” North Atlantic, 95 to 147 fathoms. 
Ampelisca odontoplax G. O. Sars. “No eyes.” North Atlantic, 142 fathoms. 
A. minutieornis G. O. Sars. “No perceptible eyes.” North Atlantic, 350 to 634 fathoms. 
Byblis abyssi G. O. Sars. “ No eyes.” North Atlantic, 350 to 620 fathoms. 
Podocerus brevicornis G. O. Sars. “ No eyes.” North Atlantic, 146 to 767 fathoms. 
P. tenuicornis G. O. Sars. “Eyes wanting.” North Atlantic, 1,110 fathoms. 
Unciolapetalocera G. O. Sars. “ No eyes.” North Atlantic, 350 to 650 fathoms. 
Dulichia macera G. O. Sars. “ Eyes rudimentary.” North Atlantic, 450 to 870 fathoms. 
Hyperiopsis'voringii G. O. Sars. Eyes rudimentary. North Atlantic, 1,280 fathoms. 
Stegocephalus gibbosus G. O. Sars. “No eyes.” North Atlantic, 120 fathoms. 
S. auratus G. O. Sars. “No distinct eyes.” North Atlantic, 100 fathoms. 
Archibenthal and abyssal mollusks are often blind, as of course you are well aware, but many are not. I have not found 
any with exceptionally well-developed eyes. The Strombs, which live in shallow water, and some of the Cephalopods 
have eyes comparable to those of vertebrates. Many embryo mollusks have eyes which they lose on becoming adult. 
Cave land shells are frequently blind. The Zonites subrupicola I described from your Utah cave was blind; and, by 
the way, I have the same species from above ground, under stones in California, since, but not with the soft parts. 
The big Auriculas (A. judce, for example) are blind. They live under dead leaves in forests. Several blind species of 
Zospeum and a Helix (Ammonitella) hauffeni are found in the grottoes of Carniola. On the other hand, the Onchidium 
of the tropics has, like some Chitons, eyes in its back, .described by Semper, besides its normal tentacular eyes, while 
the very similar northern Onchidella has only the latter. Csecilianella and Geostilbia are French cave land shells 
without eyes. The Sepia has lids to its eyes and is the only mollusk which can tip you a wink!” 
Although living snails were found in nearly all the caves examined and collections of them made, which are 
mostly in the Museum of Comparative Zoology at Cambridge, they have not been carefully examined and identified. 
None are known to be peculiar to caves, and the shells are of the normal color, not bleached. It is, however, of 
interest to observe that De Rougemont in his essay on Hydrobia found in the wells of Munich and in Falkenstein 
Cave this species, not found in the upper world. He states that the existence of eyes in this species is not positively 
proved, although Wiedersheim, who first found this snail in the Falkenstein Cave, speaks of the existence of visual 
organs on the tentacles. De Rougemont adds that in the Hydrobia from Munich he has seen no such traces: “Les 
tentacules ytaient d’nne uniformity complete de leur base a leur extremity ” (fitude, etc., p. 45). Good transverse 
microscopic sections would probably readily enable one to settle the point whether traces of eyes exist in this interest¬ 
ing mollusk. 
