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Show 1886.] SQUALORAJA POLYSPONDYLA. 529 NEW SPECIMENS. Up to the present time, therefore, there is no very precise information in regard to the structural features of Squaloraja beyond the descriptions of dermal appendages, the snout, and the vertebral column. But the British Museum again furnishes materials for aa addition to our knowledge (thanks, especially, to a recent purchase from Mrs. Dollin of Lyme Regis, and the acquisition of the Egerton and Enniskillen collections), and it is upon the national fossils that the present contribution is based. All the specimens are from the well-known Lower Lias of Lyme Regis, Dorsetshire ; and, adding Roman numerals for convenience of future reference, they may be briefly enumerated as follows :- I. The nearly complete skeleton of a male, wanting only a small portion of the caudal region, and shown of the natural size in Plate LV. fig. 1. This specimen exhibits the dorsal aspect, and is particularly interesting on account of the preservation of the limbs and limb-girdles, which have not hitherto been so well displayed. The cranial cartilages are not remarkably distinct, and the dentition is only feebly indicated ; but the form and proportions of the snout and rostral spine are very satisfactorily shown, and the vertebral column, except anteriorly, is in a comparatively good state of preservation. (Brit. Mus. no. P2276.) II. Portions of the vertebral column and the crushed cranium of an old individual, probably female. (Egerton Collection, Brit. Mus. no. p 2079.) III. Portion of the skeleton of a young female, viewed from the ventral aspect. There are only obscure remains of the cranial cartilages, but the snout and dentition are beautifully exhibited. The caudal region is also well preserved, but all traces of the abdomen have been removed and destroyed. (Enniskillen Collection, Brit. Mus. no. P3184.) IV. A fine skull of a male individual, seen from above, and exhibiting the form of the head, dentition, and rostral spine. (Brit. Mus. no. 47402.) V. A detached rostral spine, somewhat smaller and less robust than that figured by Davies (/. c. fig. 3), but equally curved, the broadened base of insertion wanting. (Enniskillen Collection, Brit. Mus. no. P3186.) VI. A complete, much-curved rostral spine, exhibiting only the superior aspect. (Enniskillen Collection, Brit. Mus. no. p 3187.) VII. The anterior two thirds of a rostral spine, probably belonging to an animal even larger than no. II. (Enniskillen Collection, Brit. Mus. no. p 4574.) VIII. An extraordinarily slender and acuminate small rostral spine, seen from the dorsal aspect. (Egerton Collection, Brit. Mus. no. p 2081.) The specimens numbered I. to IV. are almost certainly referable to the already named species, S. polyspondyla, Ag\, and owe their slight variability to differences in age, as indicated by the condition PROC. ZOOL. Soc-1886, No. XXXV. 35 |