388 Lieut.-Col. Stuart Wortley on the Habits of 



are now, I believe, in the Natural History Museum, Aberdeen. 

 I only saw a portion of these bones for a few minutes shortly 

 after they were discovex-ed, and have had no opportunity of exa- 

 mining them since; but Mr. Page (in whose possession they 

 were) stated, at the Aberdeen Meeting of the British Association, 

 that they belonged to some species of Oidemia and Somateria. 

 However this may be, there is, in the Natural History Museum, 

 St. Andrew's, the cranium of a duck, minus the bill, the zygo- 

 matic, tympanic, and pterygoid bones, that was found in the 

 brick-clay of Tyrie, near Kirkaldy. This cranium has the 

 closest resemblance to that of Oidemia nigra, but is much larger 

 than the cranium of this or any other of the genus that now 

 frequents our coasts. The skull of O. perspicillata, however, I 

 have never seen; but Gould and others represent O.fusca as 

 the largest of the genus. When the fossil cranium is compared 

 with the latter species, it is found to be a full eighth of an inch 

 larger in transverse diameter; its vertical diameter is likewise 

 greatest. The cranium of Somateria mollissima exceeds the 

 fossil in size exactly in the proportion that the latter exceeds O, 

 fusca. If the body bore the same proportion to the cranium in 

 Pliocene times as now, this Duck must have been intermediate 

 in size between O.fusca and S. mollissima. This is the more 

 remarkable when we consider the close resemblance which exists 

 between the fossil cranium in all its parts and that of O. nigra ; 

 for, excepting the larger size of the former, there appears to me 

 to be no tangible difference whatever in the crania of sufficient 

 importance to separate them specifically. The fossil cranium is 

 perhaps a little more depressed than the recent, and the post- 

 orbital processes form a rather better defined angle on each side 

 with the posterior of the orbital cavity than they do in O. nigra, 

 and in this respect somewhat resemble O. fusca. But there are 

 the superiorly approximating orbits, the upward and backward 

 ascending processes on the lachrymal (?) bones; although large 

 in the fossil, they form part of the circular ridge across the base 

 of the bill, followed by a deep median depression, as in O. nigra. 

 The foramina appear to be the same in both ; the fossil cranium 

 has likewise a single optic foramen, and well-defined grooves for 

 the olfactory nerves. 



XL. — On the Habits of Pagurus Prideauxii and Adamsia 

 palliata. By Lieut.-Col. Stuart Wortley. 



In the month of July last, while dredging on the ' Diamond^ off 

 Hastings, I obtained many specimens of this interesting Hermit 

 Crab with its lovely lilac-and-white companion. I selected a 

 pair, of convenient size, living in the shell of a Natica monili- 



