212 Jackson: A New Species of Umio. 
the south side of Robin Hood’s Bay. This specimen, however, 
has been mislaid, and is, therefore, not available for examina- 
tion. 
During Easter week, Prof. Kendall and I visited this quarry 
and succeeded in finding three further examples. The Unio- 
bed here is only 18 inches above the top of the Dogger, and 
underlies a ‘ seat-earth ’ with rootlets, on the top of which is a 
very impure coal-seam. The specimens obtained are, un- 
fortunately, too imperfect for accurate specific determination, 
but in general appearance they somewhat resemble a small 
variety of the Saltwick form. One specimen is interesting in 
possessing traces of two or three strong lire on the posterior 
slope of one of the valves. radiating from the umbo to the 
posterior margin. Whether this can be regarded as sculpture 
or not is uncertain. It may, of course, be due to crushing, as 
the shell shows signs of having undergone some lateral pres- 
sure. Until further and more perfect examples are obtained 
it will, perhaps, be wiser to defer the description of this form. 
Some specimens of a Unio were also obtained from the 
Lower Estuarine beds at Haiburn Wyke. They were dis- 
covered on breaking up a large ironstone nodule containing 
plant remains, the most abundant of which was Contopteris 
hymenophylloides (Brong). Unfortunately, all the examples 
obtained are young individuals, none exceeding three-quarters 
of an inch in length. The form is oblong oval, rounded an- 
teriorly, angulated above posteriorly, base and _ hinge-line 
curved. The test is covered by numerous fine concentric 
growth lines, and on the posterior area are, apparently, traces 
of sculpture in the form of very slight radiating nodules or 
puckerings. 
Phillips, in his ‘ Geology of Yorkshire,’* quotes a Unio from 
Haiburn Wyke, as follows :—' Unio insperatus Phil. M.S., a 
small oval species. Upper Shale, White Nab. Ironstone, in 
Lower Shale, Haiburn Wyke.’ No description or figure is 
given, and I have been unable, so far, to discover the type on 
which Phillips founded the species. Dr. Kitchin has kindly 
submitted to me two specimens of an obscure Unio from the 
Lycett Collection in the Geological Survey Museum, Jermyn 
Street, London. These were catalogued as ‘ Unio insperatus 
Phil., from Sandstone Shale, at White Nab, Scarborough.’ 
Thinking these might be Phillips’ types, I again communicated 
with Dr. Kitchin, who replied that there is no proof that 
Phillips saw or named the specimens, or that the identification 
with his species either by Lycett or somebody else, had his 
(Phillips’) approval, or was sufficiently soundly based. It is 
presumed that when the Lycett collection was purchased for 
Ssords de 1875. 
Naturalist, 
