Vol. XIII, pp. 47-51 May 29, 1899 



PROCEEDINGS 



OF THK 



BIOLOGICAL SOCIETY OF WASHINGTON 



THE EYE OF BYBLIS S ERRATA. 

 BY SYLVESTER D. JUDD, Pir. D. 



Bijhlis serraia is an Ainplii[)od Crustacean, which l)elongs to 

 the famil}' Gammavidx,, l)ut has totally different eyes from Gam- 

 mnrus. A pair of these eyes projects from either side of the 

 cei)halon and an}^ one of tliem calls to mind the vertebrate 

 eye, because it has a biconvex lens and a fluid-filled space with 

 a retina below. A section through the chief axes of the eye 

 of Bijhlis would first show a large lens, which has been secreted 

 in concentric shells by a thickened layer of lentigen, Fig. 4, I. 

 continuous on either side with the thinner hyi)odermis A, which 

 is gorged with scarlet })igment that envelops the eye |ike a cornu- 

 copia, thus shutting out all the ra3^s that might reach the retina 

 without first passing through the lens. Under the lentigen is a 

 humor space, s. Below and i)roximal to this s[)ace is a layer of 

 cokunnar cells, x, which is continuous on either side with the 

 hypodermis. This layer of cells has secreted a strong cuticula 

 on its outer l^oundary, which borders on the'space, and just })rox- 

 imal to this layer are the omatidia (which, of course, lack the 

 corneal cuticula). The most distal element of an omatidium is 

 a granular columnar body (cell product), r. Below and proximal 

 to this body, the remainder of the omatidium with its refractive 

 cone and retinulais practically identical with the omatidium of 

 GammdVHS, minus of course, the corneal cuticula, for in the re- 

 tinula of both crustaceans there are five retinal cells with pig- 

 ment and four rhabdomeres. 



Methods. 



The material employed in studying the eye of Byhlis serrata 

 was obtained at Mr. Alexander Agassiz's laboratory, at Newport, 



l:i— Hicji.. Sor. Wash., Voi,. XIII, 18',)',) (4T) 



