( 14 ) 



Fig. 6. The bare patch along the course of the umbilical vessels of left cornu of 

 the chorion of Orcella, drawn of natural size : r., right and I., left pole ; 

 d,, dorsal or anterior and v,, ventral or posterior margin ; p., peduncu- 

 lated body. 



„ 7. The surface of the chorion of JPlatanista, exhibiting bare patches, vascular 

 elevations and villous membrane, about natural size. 



„ 8. One of the chorionic bare spots and surrounding villous membrane also of 

 Flatanista^ enlarged 4 diameters. 



55 9. The internal uterine surface of Flatanista demonstrating its mucous mem- 

 brane5 with scattered irregular sized bare patches. Natural size. 



55 10. A single bare spot of the preceding specimen enlarged 4 times : the orifice 

 of a utricular gland is seen in the middle. 



PLATE XXXYI. 



Various microscopical sections exhibiting intimate structure of the skin, teeth, 

 eye, stomach and umbilical cord of Flatanista gangetica and Orcella hremrostris-^ 

 Fig. 1. A piece of the cuticle of Flatanista as seen from below, under a 2-inch 

 object glass. 



,5 2. A vertical section of the skin of the foetal Flatanista from the upper jaw 

 around one of the hairs (the latter being an appendage of a temporary 

 kind) : p., papillary layer ; c., coarse connective tissue, containing fat 

 globules ; /. m., strong fibrous and partially muscular layer with abun- 

 dance of fatty and oily tissues; h., hair or rudimentary bristle with 

 firm tissue around, and cut somewhat obliquely ; v,, a large vascular 

 space. Magnified about 15 diameters. 



„ 3. A vertical section of the skin of the snout of the young P. gangetica 

 enlarged about 6 diameters : p., papillary layer ; (?., coarse connective 

 tissue ; 5., layer of blubber, composed of masses of fat cells intermixed 

 with coarse fibrous tissue ; /., layer of coarse fibres and finer connective 

 tissue ahnost devoid of fat globules ; m., muscular layer, the bundles 

 being cut obliquely. 



„ 4. A view of a portion of a transverse vertical section of the lower jaw with 

 non-errupted tooth in situ : d. g., the dental groove, here, however, shown 

 as if opened at the top ; ep., epithelial lining of same, and in continuity 

 with (5.)5 skin of gum; c, connective or fibroid tissue of the deep skin 

 textures ; e., enamel layer of tooth reaching quite to its base ; d,, den- 

 tine only partially developed above5 and imperceptibly blending with 

 the pulp, the latter exhibiting no traces of cement or osteo- dentine ; 

 c, b., large meshwork of cancellated bone tissue5 here only yet in process 

 of formation ; v., vessels supplying capillaries to bone and tooth pulp ; 

 n., nerves immediately above. Enlarged about 5 times. 



