SMITH: EYES OF PULMONATE GASTEROPODS. 283 



EXPLANATION OF PLATES. 



Except where indicated, the figures refer to Limax maximus. They were drawn 

 with the aid of the camera lucida. The neurofibrillae were drawn under a Zeiss 



•fj homog. immersion objective. Most of the sections were 6£,u in thickness. 

 Unless otherwise stated, the Figures of Plates 1-3 are magnified 8l>0 diameters. 



Abbreviations. 



ar. bac axis of rod. 



bac rod. 



cl. cm corneal cells. 



cl. gl gland cell. 



el. pig pigment cell. 



cl. sns sensory cell. 



cp.trm end-body of rod-fibril. 



cps. opt optic capsule. 



cm cornea. 



d dorsal. 



fbrl fibrillae of sensory cell. 



fbrl' " " rod-axis. 



fbrl" " " rod-mantle. 



fbrl'" " " neurite. 



fbr. runs muscle fibres. 



hi. vit vitreous humor. 



ivlr.bac mantle of rod (involucrum). 



hi. ta involution of tentacle. 



lac lacuna. 



Ins lens. 



Ins' lens of accessory retina. 



nl nucleus of sensory cell. 



nl' " " pigment cell. 



n. opt optic nerve. 



n't neurite of sensory cell. 



n. ta tentacular nerve. 



pig pigment. 



pre. n't neurite-process of sensory cell. 



rdl radicula of sensory cell. 



rdl' " " pigment cell. 



rtn. ace accessory retina. 



rtn. ex peripheral zone of retina. 



rtn. i central zone of retina. 



rtn. in middle or pigmented zone of retina. 



v ventral. 



