1899.] BliOOD-VESSELS OF TBLEOSTEAI^^ FISHES. 941 



LiTERATUEE. 



On searching through the literature of the subject, one cannot 

 fail to be strucii by the fact that the arterial system of Teleostean 

 fishes has been very greatly neglected, and the disposition of 

 the efferent branchial vessels particularly so. Meckel and 

 Hyrtl appear to have been the only anatomists to undertake any- 

 thing like a systematic study of these latter. Meckel in 1831 

 (14. p. 192) pointed out that the mesial ends of the third and 

 fourth efferent branchial vessels are usually close together, and 

 may unite with one another before joining the aorta ; and he 

 furnished a few observations on the efferent branchial system of 

 Gaclus, Trigla, Perca, Pleuronectes, Lophius, and Munena. Seven 

 years later Hyrtl (7) gave a table showing the proportions of the 

 circulus cephalicus in fourteen species of Teleosteans, supplemented 

 by a considerable amount of information concerning the vessels 

 associated with the circulus, and good figures of the efferent 

 branchial system of Perca, Gaclus, and Tinea. 



Stanuius in 1849 (23. pi. v.) published some fairly reliable figures 

 of the efferent vessels of Cyclopterus, Gaclus, Salmo, and Scomber, 

 but the blood-vessels were only introduced into his figures to act 

 as landmarks for the recognition of the sympathetic nerves, and 

 must not be treated too critically. In his 'Handbuch' of 1854, how- 

 ever (24. p. 242), he made reference to the fact that the circulus 

 cephalicus is wide in Gaclus and Lota, where all the efferent 

 branchial vessels open into it, whereas it is narrow in Scomber and 

 Salmo, in which genera the last two open directly into the aorta. 

 The only other information on the subject is that conveyed by the 

 figures of the Carp by Duverney (6. pi. ix. figs. 17 and 18), the 

 Perch by Laurillard in Cuvier's ' Histoire Nat. des Poissons ' 

 (5. pi. vii. fig. 1), the Cod by Muller (16. pi. iii. fig. 13), the Trout 

 by Vogt (1. pi. L. fig. 2), the Pike by Maurer (13. pi. xi. fig. 1), 

 the Cod by T. J. Parker (20. p. 117), and the contributions by 

 Hyrtl on Heterotis (9), GymnarcJms (11), Chanos (12), and other 

 genera. 



GrESEBAl PakT. 



As may be gathered from the title, the observations recorded in 

 this paper concern the efferent bi-anchial vessels and the vessels 

 formed by their confluence. The cceliaco-mesenteric and sub- 

 clavian arteries usually arise in relation with the hinder part of 

 the circulus cephalicus, or with that part of the aorta which receives 

 the third and fourth efferent branchial vessels. The positions of 

 these arteries are indicated in the figures, and occasional references 

 are made to them in the text ; but the investigation does not 

 profess to deal exhaustively with these vessels, nor with the 

 hyoidean, anterior carotid and posterior carotid arteries, which 

 also are associated with the circulus cephalicus. 



The dotted lines in the figures signify that owing to the failure 

 of the injection-mass to pass, or owing to the small size of the fish, 



Peoc. Zool. Soc— 1899, No. LXI. 61 



