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Show 1 9 0 6 .] SYSTEM OF CERTAIN SPECIES OF ANURA. 1 0 1 3 (5) This branch, apparently the A. pectoralis superior, was absent on one side in one individual, but in the other three cases went irregularly to the Mm. scapulciris and infraspinatus and the scapula respectively. With regard to the other species, the two specimens of R. clamata (text-fig. 145, p. 1015) agreed with one another and with the above account in the main points. On the (right) side of the body examined, the a. thoracica superior had a forward and upward direction, going chiefly in one specimen to the M. intertransversarius capitis superior and in the other to the M. levator anguli scapulae. The thoracico-abdominalis went to the Mm. obliquus interims and transverso-scapularis major. The coraco-clav icularis passed through the coracoid foramen. The fourth branch went to the Mm.pectorales sternales and latissimus dor si and to the skin under the pectoral girdle. The fifth, which is omitted from the figure, wTent to the scapular region. In R. hexadactyla (text-fig. 147, p. 1019) there were the same five branches. The distance between the first two was much exag-- gerated in the figure to avoid confusion. The thoracico-abdominalis after supplying the M. transverso-scapularis major, ran back as an exceptionally long vessel in the substance of the Mm. obliquus externus and obliquus interims. The fourth branch was divided betwreen the Mm. latissimus dorsi and subscapular is, the cutaneous portion being absent. The fifth branch supplied the M. infraspinatus. In R. catesbiana (text-fig. 146, p. 1017) there were nine distinct branches. Their relations wTill be more easily understood by reference to the figure of this species, where, as elsewdiere, though at the risk of confusion, diagrammatic arrangement has been avoided as far as possible. Probably the third, fifth (posterior), sixth, seventh, and ninth branches are to be homologised with the five referred to above; the first, second, fourth (anterior), and eighth being additional ones. On the side of the body that is figured the third branch, presumably the thoracica superior, had completely united w ith the ramus auricularis of the cutanea so as to be distributed in common with that artery to the tympanic region. On the left side, after passing round the region of the atlas, it formed a fine anastomosis under the hinder border of the tympanic membrane with the same branch of the cutanea. A second anastomosis was formed here between the fourth (anterior) branch and a twig from the coraco-clav icularis, the latter artery passing almost entirely through the coracoid foramen. The small fourth and eighth branches followed the first and third spinal nerves respectively. R. tigrina was remarkable for the fact that the thoracica superior and the thoracico-abdominalis were each of them represented by a pair of arteries, the first pair supplying chiefly the M. intertransversarius capitis inferior, and the second pair almost wholly the M. obliquus interims. Then followed, thirdly, the coraco-clavicularis, passing wholly through the coracoid |