1879.] NATURAL SCIENCES OF PHILADELPHIA 125 



The salivary glands, the oesophagus, the stomach, and the in- 

 testine as above. The liver was in length 8.5, in breadth 4.25, 

 and in height 4 mm.; the applanation on the right anterior part 

 shorter than above. The vesica fellea as above. The sanguine- 

 ous gland and the urinary chamber as above. 



The hermaphroditic gland with its yellow lobes clothing the 

 largest part of the fore-end and the upper side of the liver. The 

 anterior genital mass about 4.5 mm. long, 3.0 in height, and 2.0 mm. 

 broad. The ampulla of the hermaphroditic duct as above, also the 

 spermato-duct and the penis, which was about 2.0 mm. long. The 

 glans short, its opening and interior clothed with an armature ; 

 this last only extended over a total length of about 0.8 mm.; the 

 hooks (fig. 18) pale yellowish, as above, rising to a height of about 

 0.016 mm. The spermatotheca and spermatocysta as above, 

 and also the spoonshaped lobe in the vestibulum. 



Note. Should the reader find any errors of proof-reading in the preceding 

 paper, he will bear in mind that Dr. Bergh has not been able to correct the 

 proofs in person and make due allowances, though it is hardly necessary to 

 remark that the utmost pains have been taken to avoid any such errors. 

 W. H. D. 



EXPLANATION OF PLATES. 



An asterisk denotes that-the drawing is by camera lucida, the 

 fraction denotes the magnification. 



Plate I. 



Aeolidia papulosa (L.) var. Pacifica. 



1. Mandible from the inside,* "; a, crista connectiva ; b, pro- 



cessus masticatorius. 



2. Part of the masticating edge,* -f 5 . 



3. Two teeth from the 'radula,* *. 



4. Another from the side,* 1 y 2 . 



5. Penis ; a, ductus ejaculatorius. 



6. Cnkhe,* ^p. 



Fiona marina (Forskal) var. Pacifica. 



7. Two teeth from the radula from above,* ^p. 



8. The hook of the same,* ^p. 



