36 ALLEN 
veins. An excellent account of the embryology of the heart 
and blood vessels was given by Hoffman (39) in 1893. In 
Vogt and Yung’s Anatomie, vol. 2, there is found a brief, but 
excellent account of the circulatory system of the perch, with 2 
colored plates. T.J. Parker (61) in his Zodtomy, 1895, gives 
the general outline of the circulation in the skate, raza nasuta, 
with 2 figures, and also a similar description and one figure on 
the circulation of the cod, Gadus morrhua. Inthe first few 
pages of Allis’ paper on Amza (3), there is a detailed account 
of the circulation in the head region, illustrated by several 
beautiful colored plates. To Jordan and Evermann (45) in 
1898, we are indebted for a systematic arrangement of the fishes 
and fish-like vertebrates of North America. In 1g00, Allis (4) 
published a complete account of the development of the pseudo- 
branchial circulation in Aza, and lastly, Briinning (10) in the 
same year was the first to work out in any detail the physiology 
of the blood vascular system of fishes. To this list might be 
added the general comparative anatomies of Gegenbour (26 and 
27) and Wiedersheim (86 and 87). 
SECTION II. TEXT. 
IV. GENERAL SURVEY OF THE BLOOD VESSELS IN OPHIODON. 
Since the blood of a fish passes around in a circle, it matters 
but little where we begin. A simple glance at Pl. I, fig. 1, will 
give an idea of the general course of the blood. The entire 
venous blood is poured into the szzus venosus (Pls. I and II, 
figs. 1 and 12; Sin.Ven.), through 6 large sinus-like vessels. 
From the rear come the hepatic veins (Pls. I and II, figs. 1 and 
12; Hep.V.), which through the capillaries of the liver receive 
the Jorial wes (P1. 1, figs. 1, 6, andia1; I. and R-Por.V*); 
bringing the venous blood from the viscera; and the ventral 
vers (Pl. I, fig. 12; L. and R.Ven.V.) conveying the blood 
from the ventral or pelvic fins and the body walls. From either 
side, the sinus venosus receives 2 large lateral trunks. The 
posterior ones or subclavian sinuses (Pl. II, fig. 12; Sub.S.) 
are the smaller, containing venous blood from the outer or 
abductor muscles of the pectoral fins; and the anterior or larger 
ones are the precaval veins or ductus cuvteri (Pl. Il, fig. 12; 
Prec.V.), which receive the venous blood from the rest of the 
