VAN NAME: SIMPLE ASCIDIANS. 
533 
1907. Halocynthia auraniium Redikorzew, Ann. Mus. Zool. Acad. St. Peters- 
bourg, vol. 11, pp. 132, 151, 154. 
1908. Halocynthia auraniium Bjerkan, Report Second Norwegian Arctic 
Exped., no. 14, p. 5. 
1908. Halocynthia aurantium Redikorzew, Trav. Soc. Nat. St. P^tersbourg, 
vol. 39, pp. 20, 24. 
1908. Halocynthia aurantium Bjerkan, Tromsoe Mus. Aarshefter, no. 25, 
pp. 60, 115. 
1908. Pyura pectenicola Michaelsen, Jahrb. Wiss. Anstalt. Hamburg, no. 
25, suppl. 2, p. 262, pi. 2, fig. 16-19. 
1909. Pyura aurantium Hartmeyer, Bronn's Tier-reich, vol. 3, suppl., p. 1339, 
1912. Pyura aurantium Hartmeyer, Denkschr. K. Akad. Wiss. Wien, cl. 
math.-nat., vol. 88, p. 182. 
Body stout and generally of rather regular more or less egg-shaped, 
barrel-shaped or pear-shaped form, attached by the smaller end. 
Siphons generally short and stout, like large papillae, the branchial 
(the larger) being almost terminal in position, the atrial on the dorsal 
surface, more or less oblique in direction, and removed a varying 
Text-flg. 2.5. — Pyura aurantium (Pallas). X 2.4. 
distance from the branchial siphon. Elongated clavate specimens 
attached by a narrow base also occasionally occur. Both apertures 
generally four-lobed, but in the case of the atrial, two pairs of these 
lobes are often practically fused, so that the aperture has the form of a 
transverse cleft. One specimen with a five-lobed branchial aperture 
was found. Test|jthin but tough and leathery. External surface 
of the body usually smooth and even, often practically free from 
wrinkles even in preserved specimens, sometimes slightly wrinkled 
with shallow circularly disposed furrows. It has, however, a granular 
