Prof. Owzw's Description of the Lepidosiren annectens. 361 
cesses of the right maxillary dental plate. c. The corresponding 
processes of the left mandibular dental plate. e, A bristle in- 
serted into the right olfactory sac, which opens upon the upper 
lip. €. The left olfactory sac laid open, exposing the double series 
of olfactory laminae. 
Figg. 3 & 4. Brain and organ of hearing of the Lepidosiren, twice natural size. 
a.a. Cerebral hemispheres. b. Optic lobe. c. Medulla oblongata. 
d. Cerebellum and fourth ventricle. e. Pineal gland. . Bilobed 
pituitary body, forming the floor of the third ventricle. g. Mam- 
millary body. À. Olfactory nerves. i. Optic nerves. X. Carti- 
laginous wall of acoustic chamber or labyrinth. J. Sac and nerve 
of smaller otolithe. m. Sac and nerve of greater otolithe. u. Se- 
micircular canals. o. Fifth pair of nerves. p. Eighth pair of 
nerves, 
5. Brain of the Menopoma. (From Meyer, Analekten fur Vergleichende 
Anatomie, tab. vii. fig. 5.) 
6. Brain of the Menobranchus. (lbid. tab. vii. fig. 6.) 
Both these figures are of the natural size. 
The same letters indicate the same parts as in Figg. 3 & 4. 
7. a. Œsophagus. b. Stomach, c. Intestine. f. Liver. g. Gall-bladder. 
h.h. Kidneys. i.i. Ureters; both are reflected downwards and 
outwards to show, x. Allantoid bladder. L. J. Ovaria, m.m. Ovi- 
ducts. n.n. Anterior apertures of the same. 
These parts are figured as seen from behind. 
3B2 
