Sprencer— 7he Blood Vessels of Ceratodus. 33 
R. ant. car.—Right anterior carotid. AR. ant. sp. art.—Right anterior spermatic artery. R. br. v.— 
Right brachial vein. A. d. c.—Right ductus cuvieri. £&. i. art.—Right iliac artery. &. a. v.—Right 
iliac vein. AR. inf. jug.—Right inferior jugular vein. A&R. lat. cut. v.—Right lateral cutaneous vein. A. 
post. car.—Right posterior carotid artery. &. ren. art.—Right renal artery. 2. post. sp. art.—Right 
posterior spermatic artery. . sup. jug.—Right superior jugular vein. A. vert. v.—-Right vertebral vein. 
Ren. port. v.—Renal portal vein, 
S.-sc. v.—Subscapular vein. S. v.—Sinus venosus. Sp. f.—Spiral fold. Sup. jug.—Superior jugular 
vein. 
V.—Ventricle. V. int. art.—Ventral intestinal artery. JV. cnt. v.—Ventral intestinal vein. 
X., (fig. 15)—Anastomotie branch between the brachial artery and the left posterior cardinal vein. 
Y. (fig. 20)—Gill-vakers. 
PLATE I. 
Fig. 1.—Diagrammatic drawing of the heart and main blood vessels, as seen from the ventral surface. 
Fig. 2.—Diagrammatic side view of the branchial arteries and the dorsal aorta, together with the main 
vessels which arise anteriorly from the latter. 
Fig. 3.—Diagrammatic drawing of the afferent and efferent branchial arteries, together with the epi- 
branchial arteries and the main arteries which arise from these vessels on the right side. 
Fig. 4.—Semi-diagrammatic drawing of a portion of a gill arch, showing the branchial Jaminz and the 
position of the afferent and efferent arteries.as seen in transverse section of the arch. 
PLATE U1. 
Fig, 5.—Diagrammatic drawing of the dorsal ends of the efferent branchial arteries and the epibranchial 
arteries, together with the main vessels arising from these. This shows especially the origin 
and course of the carotid arteries. 
Fig. 6.—Semi-diagrammatic drawing to show the relative positions of the afferent branchial arteries, the 
vessels arising ventrally from the efferent branchial arteries and the inferior jugular vein. 
Fig. 7.—Diagrammatic drawing of the veins from the hinder part of the body and the hind limbs which 
carry blood to the kidneys, together with the origin of the pelvic veins which unite anteriorly 
to form the anterior abdominal system. 
Fig. 8.—Diagrammatic drawing of the veins which enter the ductus cuvieri of the right side. 
PLATE III. 
Fig. 9.—Side view of the intestine, of which the wall of one side (the right) has been cut away to show 
the spiral fold. Whilst the drawing is semi-diagrammatic, the coiling of the fold and the 
positions of the larger vessels were drawn from an actual specimen. Three complete coils of 
the fold are exposed anteriorly, and posterior to these the six transverse series of blood vessels 
indicate the line followed by the spiral fold in the specimen. This drawing is intended to show 
the distribution of the arteries and veins in the intestine. 
E 
