‚315 
commissural arteries are united between the gills and the heart by a 
short transverse anastomosis. 
The two sunfishes dissected agreed in all particulars with the preced- 
ing account, except that in one the left lateral hypobranchial instead 
of uniting the branches from only the third, fourth, and fifth arches 
also connected with that from the sixth arch and thereby realized a 
condition found in some of the skates (cf. PARKER and Davis, ’99, 
p. 167). 
It will be seen from the foregoing description that three arteries 
arranged symmetrically reach the heart of the sunfish; these are the 
ventral coronary, drawing its blood from the third, fourth, and fifth 
visceral arches of both sides and occasionally from the sixth of one 
side, and the right and the left dorsal coronaries from the respective 
sides of the sixth arch. The conditions thus found confirm in the 
main the remarkable description given by Mine Epwarps and differ 
from it in only one particular. According to Minne Epwarps’s ac- 
count there is only one dorsal coronary (l’artere coronaire supérieure) ; 
in each of the Woods Hole specimens there were two such vessels, one 
right and one left. Since, however, these were connected by an ana- 
stomosis, it is not impossible that they may at times be replaced by a 
single vessel. 
Incidentally it may be mentioned that the heart of the sunfish 
possesses two sets of superficial veins, one (vn.) of which collects blood 
from the ventricular wall and pours it into the cavity of the ‘auricle 
not far from the auriculo-ventricular opening, while the other (vm) 
collects blood from the auricular wall and discharges it, as in most 
fishes, into the venous sinus. Since a careful inflation of the arteries 
and veins on the ventricle is followed by bubbling from the uninjured 
inner surface of the ventricles, as well as of the auricles, we may con- 
clude that the sunfish, like some other fishes (cf. PARKER and Davis, 
’99, p. 173), possesses vessels of THEBESIUS in its heart. 
This confirmation of Mine Epwarps’s description shows that a 
really remarkable condition exists in the coronary arteries of the sun- 
fish. The presence of dorsal as well as of ventral coronaries and the 
origin of the latter from more than one pair of visceral arches are 
features so universally characteristic of Elasmobranchs and so gener- 
ally absent from Teleostomes that while the sunfish has most of the 
characteristic structural features of the latter, the arteries of its heart 
ally it unquestionably with the Elasmobranchs. As the relatively simple 
coronary arteries in the Teleostomes may be regarded as derived by 
reduction from the more complex system in the Elasmobranchs, the 
