EYE OF NOTOIiYCTES TYPE LOPS. 557 



and so receiviug no innervation from the normal source, 

 come to derive their nerve sup{)]y from a twig of the 

 lachrymal branch of the ophthalmic nerve, viz. that which 

 supplies the lachryinal gland. 



The following data from one typical eye will help to give a 

 better idea of the relative sizes of the parts described : 



Length of whole conical tube . . 5'25 mm. 



Vertical diameter of conical tube (in front) . 1'14 ,, 



„ „ „ (greatest) . 1-75 „ 



„ „ „ (behind eye) 1*40 „ 



Horizoutiil ., ,, (in front) . '7 ,, 



„ „ „ (greatest) . '87 „ 



„ „ ,, (behind eye) "75 ,, 



Distance of eye from front of tube . "OG ,, 



Length of eye . . . '96 ,, 



Vertical diameter of eye . . . '87 „ 



Horizontal diameter of eye . . "85 ,, 



Length of conjunctival sac (antero-posterior) "7 ,. 



Vertical diameter of sac . . . '37 ,, 



Horizontal ,, . . . •42 ,, 



On comparison with Talpa and hjcalops [8, p. 337] it will be 

 seen that the eye of Notoryctes is slightly bigger thiin that 

 of Scalops, though distinctly smaller than that of Talpa. 



The Eyeball. 



In size this varies from '06 to I'l mm. long, -01 to I'Oo mm. 

 in vertical diameter, and "52 to *87 mm. in horizontal dia- 

 meter. 



It is enclosed completely in a tough pear-shaped capsule 

 (figs. 1, 3, 4, 2^.c.e.), consisting of closely layered fibres with 

 scattered nuclei, and occasionally with small elongated 

 patches of granular pigment in its inner part. 



Rarely one could detect a small bloodvessel running in 

 this layer. It would seem that this must be regarded as a 

 sclero-choroid, the boundary between the two membranes 



