NERVOUS SYSTEM. VERTEBRATA. 155 



nisse, Bd. viii. 1898, p. 372. (The more recent work by 

 Bela Haller [Morph. Jahrb. 1900, p. 463] is quite mis- 

 leading.) 



D. 193. The left cerebral hemisphere of a Spiny Anteater ( Tacliy- 

 glossus [Echidna] aculeatus), dissected to show the hippo- 

 campus in the lateral ventricle. 



In this specimen parts of the mesial wall have been torn 

 asunder, and as a result the exact shape of the hippocampus 

 can be seen to better advantage than in specimen D. 191. 

 The latter specimen shows the same structures, however, 

 in situ. 



D. 194. A cast of the cranial cavity of a Spiny Anteater ( Tachy- 

 glossus aculeatus). 



Gervais, Nouv. Arch. d. Mus., t. v. 1870, p. 247. 



D. 195. The optic thalami, mid-brain, cerebellum, and medulla 

 oblongata of a Spiny Anteater (Tacliyglossus [Echidna] 



aculeatus) . 



Fig. 44. (x2.) 



OPT. THAL. 



.THAL. 



ANT. QUAD. CORP 

 POST. QUAD. CORP. 



This specimen was prepared by the late Sir William 

 (then Professor) Flower (see Proc. Zool. Soc. 1864, p. 18) 

 to demonstrate the corpora quadrigeniina, concerning 

 the existence of the posterior pair of which some doubt 

 had been raised by the writings of his predecessor, 

 Sir Richard Owen. 



On the dorsal aspect (fig. 44) the small oval masses of 

 the optic thalami will be observed in front, separated by 



