156 WILLIAM BLAXLAND BENHAM. 
body wall. e./. Portion of the large nephridial funnel lying in the lateral 
mesentery, and communicating with the rectal chamber. @. Msophagus. 
@.c. Right lateral or cesophageal chamber. &. Rectum. 7. c. Rectal 
chamber. ¢.¢. The pair of “tubes,” extending from nerve-band along the 
body wall. 
Fic. 19.—Three different views of the “tubes” in transverse section. 
bt. Basement tissue. Zp. Epidermis. ¢. The “tube.” 
Fic. 20.—Two ccelomic corpuscles of different sizes. 
Fie. 21.—A blood-corpuscle. z. Nucleus. 
Fig. 22.—Portion of a section of the septum. ep. Epidermis. xe. ep. Epi- 
thelium of the nephridial duct. 2. Nuclei of cells lying in the matrix of the 
septum. c. Spaces in the septum lined by cells. 
Fic. 28.—A schematic view of the interior of the oral region of the 
body of Phoronis. The left side of the body wall and the left half of the 
lophophore are supposed to have been cut away, as well as the left lateral 
mesentery, leaving, however, the nephridial funnel. The tentacles are cut short. 
a. Gisophageal mesentery. af. Afferent blood-trunk. az. Anus. 4. Right 
lateral mesentery. 4. w. Body wall. c. Rectal mesentery. d.v. Right 
distributing vessel. d.v'. Left distributing vessel, cut away near its junction 
with the right one (these really lie close to the cesophagus and branch 
below the septum). ef. Efferent blood-trunk. ep. Epistome. g/. Glandular 
ridge and pit. g/’. Glandular pit. 7¢. Inner series of tentacles. m. Mouth. 
N.Nerve-band. 2.7. Right nephridial ridge. ze. d. Left nephridial duct, 
seen by removal of the wall of its ridge. e./. Large funnel of the left nephri- 
dium. e./". Small funnel of the left nephridium. ze. 0. Right nephridio- 
pore. @. Qsophagus. jp. Position of the “sense organ.” +7. Rectum. 
r. 7. Rectal ridge. 7. v. Right recipient blood-vessel. 7. v’. Left recipient 
blood-vessel, cut short just above the septum. s. Transverse septum.  @v. 
Tentacular vessel. 
[The dotted lines 4 B, CD, X Y, mark the levels at which the various 
transverse sections are taken. ] 
Fig. 24.—Schematic view of the aboral region of the body. The left 
body wall is supposed to be removed: the mesenteries are omitted. The 
arrows indicate the course of the blood. af Afferent blood-trunk. J. w. 
Body wall. ca. p. Branching cecal vessels from the large trunks. ef Hffer- 
ent blood-trunk. iz¢. Intestine (or “second stomach”). iz¢’. Narrow con- 
tinuation of this. o. Ovary. s¢. Stomach. 7. Testis. 
Fic. 25.—A portion of a section through the wall of the stomach. c. 
Ciliated epithelial cells forming ridges. g/. Glandular cells in crypts. x. 
Nerve. 
Fic. 26.—A portion of a transverse section of the lophophore, showing an 
