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236 Proceedings of the Royal Physical Society. 
XXI.—Variations in the Afferent Branchial Arteries of the Skate. 
By Augusta Lamont, B.Sc., Assistant in the Department of Natural 
History, University of Edinburgh. 
(With Text-figures.) 
rad 
(Received 2nd December 1920. Read 20th December 1920.) 
THE object of the following brief notes and sketches is merely to record the 
occurrence of certain abnormalities in the afferent branchial arteries of the 
skate. - 
Such abnormalities do not appear to have been described hitherto. 
Dr Gemmill, in his work on the Teratology of Fishes (1912), makes no 
mention of abnormal afferent arteries either in the skate or in any other 
Fie, 1. Raia circularis, 6. 1st June 1920. 
genus of fishes; nor does Bateson in his Materials for the Study of Variation 
(1894) give any reference to previous records of variations in these blood- 
vessels. Having failed to find any other record of abnormalities of this 
kind, the present writer has thought it worth while to describe those 
special cases which have come under her notice. : 
The material described was obtained from among skate supplied for the 
class of Elementary Practical Zoology in the University of Edinburgh. Three 
of the specimens (Figs. 4, 5, and 6) came into the hands of the writer without 
any record of either species or sex, while another specimen (Fig. 3) has the 
species alone recorded. After becoming interested in the occurrence of these 
abnormalities, the writer collected the remaining three specimens during the 
summer and autumn terms of 1920 (Figs. 1, 2, and 7), and recorded both the 
species and the sex in each case. It will thus be seen that the abnormalities, 
