296 WILLIAM BLAXLAND BENHAM. 
Fie. 1.—External view of the body wall, cut along the dorsal mid-line and 
pinned out. (Natural size.) 1 to xxvur: the first twenty-eight somites, 
showing the variation in the number of annuli to the different somites; the 
ventral edges and the folds in the sides of the Clitellum are shown. m. 
Mouth. m.p. Male pore. xe. 0. Nephridiopore. pro. Prostomium. sl. 
Lateral sete. sv. Ventral sete. spth. p. Pores of the spermathece. 
Fic. 1 a.—A flake of the cuticle, to show the two series of striz and the 
pores of the goblet-cells (p). 
Fic. 16.—Diagrammatic outline of a transverse section through the body, 
to show the position and arrangement of the sete, the relative size of which 
is exaggerated. 
Fic. 2.—General view of the contents of the body cavity, when the body 
wall has been cut along the dorsal mid-line and pinned aside. (Natural size.) 
C. g. Gerebral ganglia. Com. Commissural blood-vessels. Com’. Contractile 
“hearts.” D. Dorsal blood-trunk. dd. Doubled portion of the dorsal trunk. 
dsw. Heart-shaped dilatation of the dorsal trunk. G. Gizzard. g. Posterior 
portion of gizzard. gl. int. Intestinal glands. z¢.s. Sacculated intestine. 
int. ¢. Tubular intestine. JZ. Lateral longitudinal blood-trunk. m. 6. Muscular 
bands passing from the septa to the body wall. eps. Nephridium. ze.¢. Tubules 
of nephridium. ze. v. Vesicle of nephridium. 0. Ovary. q@s. (sophagus. 
ph. Pharynx. +. m. Radiating muscles of the pharynx. §. Septum. sem. res. 
Seminal reservoirs. spth. Spermathece. . Problematic organ attached to 
septum. 
Fic. 3.—View of the alimentary tract after removal of other structures 
that hide it, but in its natural position with reference to the septa. (Natural 
size. Somewhat diagrammatic.) B. Buccal region. G. Gizzard. yg. Pos- 
terior portion of gizzard. gi. imt. Intestinal gland (‘“‘glande de Morren”). 
int. s. Sacculated intestine. iz¢.¢. Tubular intestine. @. Misophagus. 
@. p. Pigment on cesophageal wall. ps. Pharynx. +7. m. Radiating muscles 
of the pharynx. S. Septa. ¢y. Typhlosole. 
Fic. 4.—View of somites vill to xiv after the alimentary tract has been 
removed, so as to show the genital organs. In the posterior somites the 
ventral blood-trunk has been left in, whilst anteriorly it has been removed to 
show the nerve-cord. The nephridia have been removed, except those in somite 
vil. On the right side, the seminal reservoirs have in great part been re- 
moved, to show the ciliated rosettes, and their communication with the sperm- 
ducts. (xX 2.) c. 7. Ciliated rosette. .c. Ventral nerve-cord. eo. Ne- 
phridiopores. eph. Nephridium. o. Ovary. 7.s. Rosette sac. §. Septum. 
sem. res. Seminal reservoir. sp.d. Sperm-duct. spo. Sperm pore. spth. Sper- 
mathece. (The lithographer has drawn them rather too large.) ¢pr. Testicular 
process of the seminal reservoir. V. The ventral blood-trunk. /. spt. Septal 
branch of the ventral trunk. z.y. Problematic organs in somite XII. 
Fig. 5.—The dorsal trunk and longitudinal lateral trunks, with their main 
