250 



PEOCEEDINGS OF THE JIALACOLOGICAL SOCIETY. 



had the opportunity of observing : the season also exercises some 

 influence. My specimens were collected during winter and in the 

 early spring. One living specimen measured 35 mm. in length by 

 5 mm. in breadth. 



The dimensions of a good- sized spirit specimen are : — 



1. Length over back from head to tip of tail, 33 mm. 



2. Length of sole, 31mm. 



3. Width of back, 15 mm. 



4. lireadtli of sole, 5 mm. 



5. Ereadth of groove between sole and back, 2-5 mm. 



6. Distance of anus from right tentacle, 6"5 mm. 



7. Distance of anus from pulmonary orifice, 5 mm. 



8. Distance of pulmonary orifice from head, 11mm. 



VIII. 



Athoracophorus duhius (Ckll.). 



III. Anterior portion of genitalia : mag-uified. IV. Internal wall of penis, showing 

 papillte: magnified. V. Papillic of penis wall: greatly magnified. VI. Central 

 tooth of radula, x 720. VII. Sixth tooth of radula, x 720. VIII. Jaw, 

 X 15. IX. Digestive system, enlarged. 



Lettering of the Figures. 



alh.gl. alhiiraen gland. v.d. vas deferens. 



h,d. hermaphrodite dnct. B.m. hnccal mass. 



h.gl. henna])hrodite gland. s.g. salivary glands. 



ov. oviduL't. oe. O'sophagns. 



ov'. free oviduct. c. crop. 



pr. prostate. St. position of stomach. 



p. penis. L. liver. 



r.m. retractor mnscle. I. intestine. 



r.s. reccptaculnm seminis. II. rectum. 



V. vestibule. 



