THE 
GEOLOGICAL MAGAZINE. 
NEW. SERIESHMDECADE, til "VOLIE VE 
No. IX.—_SEPTEMBER, 1888. 
Suse MEIN (Adi)  YNVISjaban Oar aay S- 
= 
I.—On a New Species oF Acer From THE Lower Litas, oF 
Witmcotre, WARWICKSHIRE. 
By Henry Woopwarp, LL.D., F.R.S., V.P.G.S., 
of the British Museum (Natural History). 
(PLATE XI.) 
HE genus Afger of Miinster was established in 1839, to contain 
some of the most beautiful forms of Prawn-like Crustacea found 
in the Solenhofen Limestone of Bavaria (see Beitriige, vol. ii. p. 64). 
Dr. Oppel, in his Paleontologische Mittheilungen (Stuttgart, 1862), 
p- 109, thus defines the genus : 
The inner antennz (antennules), with their long bifid filaments, 
start from three strong basal articulations, and attain in most 
specimens to twice the length of the whole body. The antennal 
scales are thin and very long. The basal joints of the inner antenne 
are finely serrated along their border. ‘They are much elongated, 
and project further in front of the head than the outer antenne, as 
is the case in the existing Shrimps. 
The rostrum of the cephalothorax forms a long and slender spine 
with several small tubercles along the sides. It may even attain 
the length of the cephalothorax. These characteristics may not 
however all be constant in the genus ger. 
The outer maxillipeds or jaw-feet are of great length, and are 
furnished on either side with a row of slender moveable spines of 
considerable length. A very small spine usually springs from the 
base of each of the larger spines. The first three pairs of true 
thoracic feet are chelate at their extremities, and are also. partially 
covered with similar moveable spines. 
The first pair of chelipeds are the smallest, the second are some- 
what larger, whilst the third pair are always the largest. 
The fourth and fifth pairs of legs are monodactylous, and are 
generally very long and slender, but vary in different species. 
The surface of the whole of the integument is thin, but very finely 
granulated, even the caudal plates displaying this character. 
The form of the abdomen furnishes no marked peculiarities. The 
false abdominal feet with their basal articulations are frequently 
preserved. The outer caudal lamella are divided diagonally by a 
line of articulation near their distal extremity. 
Through the kindness of the Rev. P. B. Brodie, M.A., F.G.S., 
DECADE III.—VOL. V.—NO. IX. 25 
