88 GRIFFIN. 



Plate IV. 



Fig. 21. Outline of cesopha^s, crop-gizzard, stomach, and hepatic ducts, 

 showing the course of the stomatogastric nerves, x 1.5. 



22. The ventral surface of the anterior genital mass. Natural size. 



23. The reproductive organs lying in their natural positions. The 



anterior genital mass lies upon the surface of the liver. Natural 

 size. 



24. Outline of the right side of the head of an Aclesia freeri sp. nov. 



showing the everted penis. Natural size. 



25. The dorsal surface of the prepuce. X 4. 



26. A tentacle having an unusual development of villi. 



27. Lateral view of the radula. X 4. 



28. Dorsal view of the radula. X 4. 



29. Ventral view of the radula. X 4. (Drawn by Espinosa.) 



Plate V. 



Fig. 30. Arterial system of Aclesia freeri sp. nov. 



1, pharyngeal artery. 



2, artery of pleuro-pedal ganglion. 



3, artery of median portion of foot. 



4, artery of right body wall and parapodia. 



5, aorta. 



6, arteries entering wall of spermatheca. 



7, artery of body wall in the region of the seminal furrow. 



8, artery of sperm-oviduct and left side of vulva. 



9, artery of sperm-oviduct and vulva. 



10, artery of sperm-oviduct. 



11, osphradial artery. 



12, genital artery. 



13, artery of hermaphrodite duct. 



14, artery of oviduct (albumen gland.) 



15, artery of mucous (nidamental) gland. 



16, artery of right side of albumen gland. 



17, artery of ventral surface of albumen gland. 

 18 and 19, intestinal artery. 



20, hepatic branch. 



21 and 23, deep hepatic branches. 



22, gastric artery. 



24, artery of left side of foot, left body wall, and parapodium. 



25, artery of foot. 



26 and 27, artery passing along dorsal side of crop and oeso- 

 phagus. 



28, branch to dorsal wall of head. 



29, branch to ventral wall of head. 



31. The auricle and ventricle in the pericardium. Natural size. 



• 32. The base of the ventricle, to show the large auriculo-ventricular 



valves, and the arrangement of muscles in the wall of the 



ventricle. The wall of the auricle is spread out around the 



base of the ventricle. X 4. (DravTn by Griffin and Espinosa.) 



