334 Mr. E.R. Lankester on the Anatomy of the Limpet. 
3. Xerus trivittatus, Gray, Ann. & Mag. Nat. Hist. 1842, 
vol. x. p. 264. 
Xerus getulus, Temm. Esq. 124? 
Fur dark grey-brown, white-and-black-punctulated ; vertebral 
line rather paler; throat, chest, streak on sides of back, and 
part of the sides white; belly nakedish, black: tail black-and- 
white-varied ; hairs white, with three black bands. 
Hab. North Africa, Morocco (Drummond-Hay). B.M., type. 
The specimen in the Museum, which I described in 1842 as 
X. trivittatus, was said by Mr. Leadbeater, from whom it was 
obtained, to have come from India; but I have no doubt he was 
misled; and we have lately received living specimens direct 
from Morocco, some of which are preserved in the Museum. 
This species differs from X. setosus in the spines being thinner, 
shorter, less rigid, the vertebral line paler, the sides white, and 
the belly black. The black hairs are not so abundant, and 
they are not to be observed amongst the white spines that form 
the streaks. 
XLITI.—On some undescribed points in the Anatomy of the 
Limpet (Patella vulgata). By E. Ray Lanxester, Christ 
Church, Oxford. 
Art the late meeting of the British Association I drew attention 
to certain structures in connexion with the digestive and urinary 
apparatus of the Limpet which had not been previously recorded, 
and which have some importance as bearing on the general 
morphology of the prosobranchiate Gasteropods. Although I 
have not yet completed my drawings or fully worked out my 
notes, I am anxious to give here a brief record of their substance. 
Since Cuvier’s memoir on Patella, M. Milne-Edwards has 
written on the circulatory organs of that mollusk, and MM. 
Robin and Lebert have briefly noticed the generative organs, 
and other authors have paid attention to the nervous system. 
The points which I believe have been overlooked are :-— 
Ist. The existence of an orifice on each side of the “ head,” 
in the angle formed by its junction with the muscular foot, and 
opening into the blood-sinus surrounding the pharyngeal vis- 
cera. These orifices I propose to call the capito-pedal orifices. 
2nd. The existence of a pair of very large, orange-coloured 
salivary glands opening by four ducts (two on each side) into 
the buccal cavity. 
3rd. The peculiar laminated “crop,” like that of Chiton, re- 
sembling in structure the psalterium or manyplies of ruminants. 
