” 
352 THE AMERICAN NATURALIST. (VoL. XXXIX. 
veins in Raia c/avata L. as opening each into the corresponding 
renal portal vein. 
Hochstetter ('88) gives the following account of the lateral 
veins of Spinax [= Squalus] acanthias: “Neben den Venæ sub- 
clavie münden caudalwärts von ihnen jederseits eine Vene, in 
die Cardinalvenen, die Seitenvene..... Diese beiden Gefässe 
wurzeln in einem Venennetze, welches die Kloake umspinnt und 
mit den Pfortaderzweigen des Enddarmes anastomosirt. Aus 
diesem Netze gehen rechts und links die beiden Venen hervor, 
welche angeschlossen an die dorsale Fläche des Beckenknorpels 
zunächst die Vene der hinteren Extremität aufnehmen und 
hierauf umbiegend, geradeaus kopfwárts verlaufen und auf diesem 
Wege die Venen der Bauchmuskeln aufnehmen " (p. 126). In 
the rays, Hochstetter says, the lateral veins exhibit substantially 
the same condition as that described for Squalus. 
We were led to investigate the posterior connections of the 
lateral vein of the skate owing to the fact that, in the numerous 
animals which had come under observation in the laboratory, 
there had never been seen the least evidence of the “ ilio- 
hemorrhoidal” trunks described by Parker for Raza nasuta. In 
a freshly-killed skate (R. erinacea or R. levis, Fig. 4) the lateral 
veins, lying just beneath the peritoneum, are conspicuous ves- 
sels because of the blood contained in them. They may be 
followed back to the pelvic region, where they disappear from 
view. The cardinal sinus is usually well filled with blood and a 
posterior extension of this sinus may be traced back to the base 
of the rectal gland. This extension evidently corresponds to 
the “hinder prolongation of the cardinal sinus” described by 
Parker as receiving the ilio-hæmorrhoidal veins, but no large 
trunks are to be seen opening into it. Attempts to trace the 
uninjected vessels by dissection resulted negatively, so far as any 
connection between the hind end of the lateral vein and the car- 
dinal sinus is concerned, although a connection of the lateral 
vein with a vein from the pelvic fin was found. Furthermore, 
observation of a large number of injected skates had given no 
evidence of the existence of “ilio-hæmorrhoidal ” veins. These 
injections, however, being of raw starch or of plaster of Paris, 
were not calculated to show a connection between lateral vein 
