290 MR. A. O. WALKER ON THE 
Fig. 4. Drawing of wax model of Left Upper Deciduous Molar. Postero- 
internal view. Stage III. 
5. Section through Left Upper Permanent Incisor, showing Labial down- 
growth of Dental Lamina. Stage I. 
6. Section through Successional Molar. Stage ITI. 
7. Orown-surfaces of the last two Upper Molars of 
A. Dolichotis platycephalica (after Ameghino). 
B. Cavia cobaya. Both much enlarged. 
8. Crown-surface of Upper Molar of 
A. Stichomys constans. Inferior Eocene (after Ameghino). 
B. Spaniomys riparius. 5 ob 3: 55 
C. Hystrix leucura. Recent. (Camb. Univ. Zool. Mus.) 
9. Section through Deciduous and Successional Molars of Cavia, showing 
“concentric epithelial body ” in connection with the former. Stage IT. 
10. Section through a Posterior Molar, showing lateral position of the 
root. 
Contributions to the Malacostracan Fauna of the Mediterranean. 
By AtFrep O. Waker, F.L.S. 
[Read 7th March, 1901.] 
(PLATE 27.) 
Tue following results of a short stay at Cannes and Hyéres are 
interesting as showing what may be done in a few hours’ 
dredging from an open boat, in depths never exceeding 35 fath., 
and with the simplest apparatus. This consisted of a tow-net 
of tiffany (such as is used by gardeners for shading greenhouses), 
strengthened at the bag end by cheese-cloth sewn over it for 
about 2 ft. in length, and attached to a cane rim 6 or 8 in. in 
diameter. The cane is important, as the net should be as light 
as possible so as not to scoop up the sand, in which case it fills 
up immediately. This net is attached to a stone heavy enough to 
remain on the bottom while the boat is rowed rather quickly ; the 
distance of the net from the stone varying from 3 feet on coarse 
sand to 6 feet or more on mud. The stone stirs up the 
Crustacea, which find their way into the net with a certain 
amount of sand, though far less than in the case of a dredge 
(however light), or metal-rimmed tow-net. This, with two small 
buckets such as are used by children at the sea-side, a small 
muslin-bag attached to a brass rim with a brass grating on the 
top, two or three glass jars (e.g. French-plum jars), 75 fathoms 
of line, and plenty of tubes large and small, constitute the 
