374 ON THE STRUCTURE OF THE EYE IN ARCTURUS. [May 6, 



during 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 l873-7(>. — Part I. The genus 

 Serolis. Zool. Chall. Exp. pt. xxxiii. 



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. xhiii. 



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

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



5. Grenacher, 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 Anomura collected by 



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

 Exp. pt. Ixix. 



8. Pelseneer, p. — Report 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. vol. 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 OP PLATE XXXI. 



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

 body; rh., rhabdom ; r., rotinula; n., nuclei of retinula-eells. The chitinoua 

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



yellow. 



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



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



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



5. Longitudinal section through ommatidiuni of A furcatus. 



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



rueuted preparation. 



7. Partially depigmented retinula of A. furcatus. 



8. Depigmented retinula of A. furcafus. 



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



rhabdom ; one rhabdomere is seen. 

 10. Longitudinal section through ommatidium of A. spinosus. 



