3/4 ON THK STRUCTURE OF THE EYE IN ARCTURUS. [May 6, 



durins; the Voyage of H.M.S. ' Challenger.' — Part I. Serolis. 

 P. Z.S. 1884, p. 330. 



2. Beddard, F. E. — Report on the Isopoda collected by H.M.S. 



'Challenger' during the years l!S73-7().— Pait I. The genus 

 Serolis. Zool. Chall. Exp. pt. sxxiii. 



3. Beddard, F. E. — Report on the Isopoda collected by H.M.S. 



'Challenger' during the years 1873-76.— Part II. Zool. Chall. 

 Exp. pt. xlviii. 



4. Beddard, F. E. — On the Minute Structure of the Eye in the 



Cymothoidae. Trans. Roy. Soc. Edinb. vol. xxxiii. p. 443. 



5. Gren.acher, H. — Untersuchungen liber das Sehorgan der 

 Arthropoden. Gottingen, 1879. 



6. Hoek, p. P. C. — Report on the Pycnogonida collected by 

 H.M.S. 'Challenger 'during the years 1873-76. Zool. Chall. 

 Exp. pt. X. 



7. Henderson, J. R. — Report on the Anomnra collected by 



H.M.S. ' Challenger ' during the years 1873-76. Zool. Chall. 

 Exp. pt. Ixix. 



8. Pelseneer, p. — Keport on the Anatomy of the Deep-sea Mol- 

 lusca collected by H.M.S. ' Challenger 'in the years 1873-76. 

 Zool. Chall. Exp. pt. Ixxiv. 



9. Lankester, E. R., and Bourne, A. G. — On the Minute 

 Structure of the Lateral and Central Eyes of Limulus and 

 Scorpio. Q. J. Micr. Sci. toI. xxiii. p. 177. 



10. Packard, A. S. — The Cave Fauna of North America, with 



Remarks on the Anatomy of the Brain and Origin of the Blind 

 Species. Mem. Nat. Acad. Sci. vol. iv. 



11. Watase, S. — On the Morphology of the Compound Eyes of 



Arthropods. Stud. Biol. Lab. Johns Hopkins Univ. vol. iv. 

 no. 6, p. 287 et seq. 



12. Smith, S. I. — Abyssal Decapod Crustacea of the * Albatross' 

 Dredgings in the North Atlantic. Ann. & Mag. Nat. Hist. (5) 

 xvii. p. 187 et seq. 



13. Patten, W. — Studies on the Eyes of Arthropods. — I. De- 

 velopment of the Eyes of Vespa, &c. Journ. Morph. vol. i. 

 no. 1. 



EXPLANATION OF PLATE XXXI. 

 The following letters have the same significance in all the figures : — v., vitreous 

 body; rk., rhabdom ; r., retinula; «., nuclei of retinula-ceUs. The ehitinous 

 parts of the eye (vitreous body and rhabdom) are for the most part coloured 

 yellow. 



Fig. 1. A number of ommatidia of Arcturus spinostis, from above. 



2, 3. Cross sections at different levels through rhabdom of A. spinosus. 



4. A number of ommatidia of A. furcatus, from above. 



5. Longitudinal section through ommatidium of A furcatus. 



6. Vitreous body and rhabdom of A. spinosus, from a teased and depig- 



mented preparation. 



7. Partially depigmented retinula o( A. furcatus. 



8. Depigmented retinula of A. furcatus. 



9. Transverse section of ommatidium of A. furcatus below extremity of 



rhabdom; one rhabdomere is seen. 

 10. Longitudinal section through ommatidium of A. spinosus. 



