Plate VI. 



Vol. IV. 



ANATOMY OF HELIX ASPERSA. 



Fig. 1. — The shell has been removed by cutting along the suture. The respiratory chamber 

 is laid open by a cut extending from the respiratory orifice along the transverse line effusion 

 of the mantle, and by another cut on the right side, passing backwards along the extreme 

 right hand limit of the chamber, so as to leave the anus, rectum, and kidney in continuity 

 with the mantle-roof of the chamber. A complete view of the digestive organs has been 

 obtained by opening the dorsal integument by a median cut extending from the head to 

 the spirally twisted hump, and by carefully separating the alimentary tract from its attach- 

 ments. The liver has been partially removed in order to e.xpose the convolutions of the 

 intestine, and the generative organs have been pushed to the right side. 



R. rectum — k. kidney — h. heart — a. anus — i. intestine — 1. liver — st. stomach — B.V. 

 blood vessels — sal. salivary glands — sd. sd. ducts of the same — N. nerve collar — Lot. 

 left oculiferous tentacle — M. mouth — h.gl. hermaphrodite gland — alb. albumen gland — 

 ovsp. ovisperm duct — ov. oviduct — sp. sperm duct — va. vagina — ds. dart sac — di. dilutant 

 glands — spth. spermatheca — ap. appendix — pe. penis sheath— fl. flagellum. 



Fig. "2. — In this diagram the nerve collar and chief nerves are shown. The oesophagus 

 has been drawn forward and then cut through in front of the collar, while the buccal mass 

 has been turned upwards and forwards so as to expose its ventral surface. 



Cer. cerebral or supra-oesophageal ganglion pair, giving off a pair of nerves to the 

 buccal ganglia (hue) — t' t" nerves from the cerebral ganglion to the great and small tentacles 

 — inf. infra oesophageal ganglion — nn. nerves from the same to foot, &c. — R. Scharff. 



