Vascular System of Bdellostoma dombeyt. 4 
Wn 
peu, . . pericardial cavity. supr.int, supra-intestinal vein. 
pha, . . posterior hepatic artery. sn, . . . “intercostal” nerve. 
roc, . .red blood corpuscles. sgl, . .slime glands. 
r, . . .renal branches. sav, . . sinu-auricular valves. 
SPC, spinal cord. ty . somatic vessels. 
sub. int, sub-intestinal vein. vu, . . . valves of portal heart. 
scd, . .superficial anterior car- ug,..- vagus nerve. 
dinal. ca . . §*ductus Botalli,” 
In figures IV, V, VI, red line indicates peritoneum; in all 
other figures—red, arteries; blue, veins; green, portal vessels. 
EXPLANATION OF PLATES. 
Plate I includes Figures I-IX. 
Plate II includes Figures X-XVI. 
Plate III includes Figures X VII-XX. 
FiIcurE I.— Heart of Adellostoma dombeyi (Xt). Dorsal view. 
A, auricle. V, ventricle. S, sinus venosus. BA, bulbus aorte. jv, 
inferior jugular vein. acl, left anterior cardinal. pec, posterior com- 
mon cardinal. ha, anterior hepatic vein. hp, posterior hepatic vein. 
FIGURE I].—Heart of Adellostoma dombeyt (1). Ventral view. 
Lettering same as in Fig. I. 
FIGURE III.— Heart of Adellostoma dombeyi (2). Showing a dor- 
sal view of the ventral half of the auricle and ventricle, the dorsal half 
having been removed by a horizontal section. 
sav, sinu-auricular valves. avv, auriculo-ventricular valves. av, aorta 
valves. Otherwise as in Fig. I. 
FIGURE IV.— Diagram of cross section passing through the mid- 
abdominal region of Bdel/ostoma. 
M, mesentery. A, alimentary canal. ptc, peritoneal cavity. 
FIGURE V.— Diagram of cross section passing through the posterior 
lobe of the liver in Bdellostoma. 
I, liver. 
FIGURE VI.— Diagram of cross section passing through the ventricle 
and anterior lobe of the liver. Showing the relation of the pericardial 
cavity to the general peritoneal cavity. 
pef, pericardio-peritoneal foramen. pcv, pericardial cavity. 0, outer 
or parietal layer of the pericardium. i, inner, or visceral pericardial 
layer. me, mesocardium. V, ventricle. Dotted line, pericardium, 
FIGURE VII.— Testis of Bdellostoma dombeyi (2), showing the 
arterial supply. The genital fold lies on the right side of the mesentery. 
wS, mesenteric artery. qs, genital branches. T, lobules of testis. 
Ap, posterior dorsal aorta. 
FIGURES VIII AND XIV.— Highly magnified portions of the smallest 
branches of a gill leaflet (450). 
cap, capillary wall. ep, epithelium lining gill cavity. rbc, red blood 
corpusles. con, connective tissue. 
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