£120 Umio distortus (Bean) and Alasmodon vetustus (Brown). 
prominent ; lunule and ligament distinct ; anterior and pos- 
terior sides rounded; hinge line fairly straight; ventral 
margin curved; external surface with well-defined growth- 
lines, which are somewhat puckered at the posterior end. 
Dimensions :—Length, 3,8* inches; height, 2 inches; 
thickness, uncertain. 
Geological Horizon: Estuarine Series (‘ Coal Shale’). 
Locality : Gristhorpe Bay, Yorkshire. 
‘These notes afford a good opportunity to call attention 
to an article by Dr. M. C. Stopes, on ‘ The Flora of the Inferior 
Oolite of Brora (Sutherland)’,* in which, on page 381, the 
authoress remarks: ‘ There were no animal remains among 
the plants, except a single example of a Unio, which was pre- 
sumably a freshwater form: it could not be specifically identi- 
fied.’ This specimen has since been presented to the Manchester 
Museum; I have thus had an opportunity of examining it. 
It consists of an imperfect right valve, measuring 2 inches in 
length, and 1 inch in height, and is preserved.in a block of 
ironstone. Unfortunately, the specimen is not perfect enough 
to determine its true specific characters, but in general shape 
and appearance it closely resembles the Umio distortus from 
the Yorkshire Estuarine Beds, and taking into consideration 
the fact of the fossil flora being so strikingly like that of the 
Inferior Oolite of Yorkshire, it does not seem at all unreason- 
able to suppose that the Brora Unzo is to be referred to Unio 
distortus Bean. 
In 1909, the Manchester Museum also came into possession 
of another fossil Unio, through the kindness of Mr. D. M. S. 
Watson, who collected it from the Great Estuarine Series in 
the north of the island of Eigg. This specimen consists of an 
impression in hard dark-coloured sandstone of a left valve, 
and shews the pseudocardinal teeth very clearly, but the 
presence of posterior lamellz is uncertain owing to the im- 
perfect condition of this portion of the fossil. The shell, which 
appears to be immature, measures 1? inches in length, and is 
I inch in height. Like the Brora example, it approximates 
very closely to Unio distortus. 
Prof. Ed. Forbes, in his paper “ On the Estuary Beds and the 
Oxford Clay at Lock Staffin, in Skye,’f mentions the occurrence 
of a Umio in these beds as follows :—{p. 111], ‘Unio? staffin- 
ensis, pl. V., fig. 5a and 5b. I have given this name pro- 
visionally to impressions of a bivalve having the form and 
aspect of a small Unio. It is transversely oblong, inequila- 
teral, depressed, truncated anteally, rounded and narrowed 
* *Q.J.G.S.’, vol. LXIIL.:(1907),-pp. 375-382; -and pl. Soe VaL 
i O.)-G:s= vol, VAIS (785) pp. io4-1 me- 
Naturalist, 
