FROM GURNET BAY, ISLE OF WIGHT. B47 
face of a fine yellow marl or pipe-clay, full of the rootlets of aquatic 
plants, and is represented by a group of ten individuals. 
The specimen measures 163 millims. in length and 102 millims. 
in breadth. In outline this species is much more oval than fig. 1. 
The head is less deep, but broader, and the eyes less conspicuous and 
placed more in front. The head is 4 millims. broad and 2 millims. 
deep. 
The segments of the thorax (pereion), seven in number, are con- 
siderably arched, the three median segments being not only broader 
but deeper than the rest. As in fig. 1, the anterior thoracic somite 
is developed laterally, so as to enclose the sides of the head. The 
length of the thorax is 8 millims., breadth 10 millims. 
The caudal shield (pleon) is large and nearly semicircular, being 
6 millims. long by 8 millims. broad. 
Two lamelliform appendages (uropoda), articulated to and arising 
from the sides of the abdomen, closely encircle the caudal shield. 
A small ramus is given off from the second (third?) articulation of 
the uropodite, as in recent Spheromide. ‘Traces of antenne can 
also be detected on the slab, but no other appendages are preserved. 
I have designated this form Hospheroma Smithii, after its dis- 
coverer, Mr. E. J. A’Court-Smith. 
Tt must not be supposed that these remains occur Dacgue ten the 
bed described. The bed itself is at most 12 inches thick, ‘bub more 
often only 2 inches. Thousands of blocks of this fine hard-grained 
limestone have been broken up, in the course of the last twenty years, 
by Mr. A’Court-Smith to obtain specimens. 
I subjoin a short description of the French Kocene form described 
by Prof. H. Milne-Edwards*, which I propose to refer to the same 
genus with those from the Isle of Wight (see Pl. XIV. fig. 3):— 
** This Isopod was found in the neighbourhood of Paris, in digging 
the fortifications at the hill of Chaumont ; it was met with in a bed 
of marl, immediately below the green marl containing Cytheret. It 
is so abundant that sometimes in the space of a square foot one can 
count the impressions of more than a hundred individuals. 
“The form of these little Crustaceans is pretty regularly oval ; 
the largest individuals measure only about 12 centims. [sic|¢ long 
by 7 or 8 broad. 
“The body appears to have been depressed, as in Ancinus, for the 
impressions left do not exceed half a centimetre [sie] [read “ milli- 
metre”’| in thickness, and present no appearance of deformation. 
* The head is of medium size, and gives insertion to the antennz 
by a slight frontal flattening; the eyes are small and placed 
laterally. 
“The thorax (pereion) is composed of seven rings, and presents 
* Seo ‘ Annales des Sciences Naturelles,’ 2° série, 1843, tome xx. Zoologie, 
p. 329. 
t [Lower Tertiary. | 
{ [For “centimetres” read ‘“ millimetres.” This is evidently an uncorrected 
printer’s error, as the specimens, with Prof Milne-Edwards’s label, are now 
before me, and do not exceed about 12 millims. ] 
