MOLLUSCA 



203 



Anomalous types of eyes are seen among Cephalopods found at great ocean 

 depths (Chun, 1903). Stalked eyes comparable to those found in some deep-sea 

 fishes, are exemplified in Bathothauma (Fig. 194) and Srindalops (Fig. 195) ; both 

 of these live at great depths in the South Atlantic and the eyes of the latter are 

 unic£ue in that they point obliquely downwards, a curious configvu'ation said to be 

 explained by the fact that the squid swims with its body slanting upwards. 



Figs. 19-1 to 196. — The Eyes of Dkep-sea Cephalopods. 



Fig. 19.5. 



Fig. 194. 



Fig. 196. 



Fig. 194. — The deep-sea squid, Bathothauma. There are luminous organs 

 beside the eyes which are perched on the end of stalks. Found at a depth 

 of 3,000 m. (from the Valdtvia Reports). 



Fig. 19.5. — The deep-sea squid, Sandalops melancholicus. The stalked eyes 

 are unique in that they point obliquely downwards, possibly because the 

 animal swims with its body slanting upward (from the Vahlivia^ Reports). 



Fig. 196. — The pelagic octopus, Amphitretus. The tubular eyes point 

 upwards and the whole body, including the eyes, is covered with a delicate 

 gelatinous covering (from the Valdivia Reports). 



Another curious arrangement is seen in Amphitretus (Fig. 196) found in the Indian 

 and Pacific oceans. The eyes of this octopod resemble the tubular organs of 

 some deep-sea fishes, i pointing directly upM^ards and enclosed, as is the entire 

 body of the animal, in a delicate and transparent gelatinous covering. 



Boulet. C. B. Soc. Biol. (Paris), 148, I486 



(1954). 

 Carriere. Die Sehorgane der Ticre, Miin- 



chen(1885). 

 Arch, niikr. Anat., 33, 378 (1889). 

 Chun. Verhdl. dtsrh. Zool. Oes., 13, 67 



(1903). 

 Crozier. J. gen. Physiol.. 2, 627 (1920). 

 Folger. Anat. Rec, 34, 1 b5 (1927). 

 Galati-Mosella. Motiit. Zool. ital., 26, 75 



(1915). 

 Hecht. J. gen. Phi/xioL, 1, 545, 657 



(1919) ; 2, 337 (1920). 

 v. Hess and Gerwerzliagen. ^4rc/(. vergl. 



Ophthal.,^, 300 (1914). 

 He.sse, R. Z. ^ris.<.■. Zool.. 68, 379 (1900) ; 



70, 347 (1901) ; 72, 565, 656 (1902). 

 Das Sehen der niederen Tiere, Jena 



(1908). 



' p. 



Kishinouye. J. Coll. Scl. Imp. Univ. 



Japan. 4, 55 (1891) ; 6, 279 (1894). 

 Light. J. Morphol. Phi/siol.. 49, 1 (1930). 

 Moseley. Ann. Mag. not. Hist., 14, 141 



(1884). 

 Mtiller, J. Ann. Sci. nat., 22, 5 (1831). 

 Nowikoff. Z. wiss. Zool., 88, 153 (1907). 

 Patten. Mitt. zool. Stat. Neapel, 6, 546, 



568, 605 (1886). 

 Pieron. C. R. Soc. Biol. (Paris), 93, 1235 



(1925). 

 Plate. Zool. Jb., Suppl. 4, 1 (1899). 

 Prince. Te.ras J. Biol. Med., 13, 323 



(1955). 

 Tompsett. Liverpool marine biol. Comm. 



Mem., 32, 1 (1939). 

 Wenrich. J. anim. Behav., 6, 297 (1916). 

 Willem. Arch. Biol.. Gand. 12, 57 (1892). 

 322. 



