14 JAS. p. HILL. 



Appendix. 



Organisation of Embi'yo, P. obesula. 

 (Plate 1, fig. 3.) 



Measurements. — Greatest length, occiput to rounded 

 hinder end of body, 12"5 mm. Head length 6'5 mm. 



Form of Body. — Head raised, but not so much as in 

 new-born, and forming an acute angle with the trunk. Pro- 

 minent snout. Slight neck protuberance. Lips fused late- 

 rally to form " Saugmund," the line of junction still 

 recognisable. Mouth lozenge-shaped. Tongue projects 

 prominently from mouth, and is grooved dorsally. Eyes 

 distinct, roughly oval in shape, and not covered by epi- 

 trichium. Eyelids not yet united. Position of lachrymal 

 duct recognisable. Position of external ear just recognis- 

 able, covered by epiti'ichium. In front of cloacal opening is 

 a small projecting '' genital Hocker." 



Limbs. — Much as in new-born, except that the claws are 

 less developed. Fore-limb flexed at elbow, and palmar sur- 

 face directed backwards. The first and fifth digits quite 

 small tubercles ; second, third, and fourth provided with 

 short, blunt, recurved claws ; the third digit the largest. 

 Hind limb paddle-like, with plantar surface directed me- 

 sially. Digits all indicated, but not free from each other ; 

 the fourth the largest. 



Notochord and Vertebral Column. — Notochord intra- 

 vertebrally constricted. Marked cartilaginous centra with 

 transverse processes and neural arches, the latter not yet 

 united above the spinal cord. 



Nervous System. — Marked fissura arcuata along mesial 

 hemisphere wall. Corpus striatum not yet prominent. Bud- 

 ding from hypophysis anteriorly, but not very marked. 



Eye. — Outer wall of optic cup about half pigmented. 

 Ovalish lens cavity. Optic stalk solid in its middle portion. 

 Eyelids not yet united. Eye muscles developing. 



