1880.] NATURAL SCIENCES OF PHILADELPHIA. 123 



Ghromodoris Calif orniensis, Bergh. 



5. Hinder part of the body, from the under side, with 6 knot* 



on the mantle-margin ; a, foot,* ^f ^. 



6. Upper median part of the true mouth,* ^|^. 



7. Part of 4 series of hooks of the lip-plate, from above,* ^f^.. 

 8-10. Elements of the same, in different positions,* ^^^. 



11. Three innermost plates ; a, the first,* ^f^. 



12. One of the largest plates,* ^^^. 



13. Hook of 3 larger plates, obliquely, from the foreside,* ^f^. 



14. Four outermost plates; a, outermost,* ^f^. 



15. Two irregular outermost , plates ; a, outermost,* ^f^. 



Acanthodoris cxj-ulescens, Berg:h. 



16. Series of plates; a, two lateral plates; 6, the outermost of 



the external plates,* ^^^. 



Triopha modesta, Bergh. 



17. Part of one of the hindermost series of plates (in the slieath), 



with (a) 4 lateral plates and {b, c) 2 external plates,* ---f^. 



18. o, second and &, third large lateral plates, from above and 



from the back,* ^K 



19. a, fourth ; h, fifth plate (as in fig. 18 from the tongue),* -^^. 



20. Outer false plate of the rhachis (from the sheath),* 3,\^. 



Tr-iopa clavigej^a (M.). 



21. a, second lateral plate; 6, two external plates,* ^f^. 



22. First lateral plate,* ^|^. 



Plate YII (XV). 



Triopha modest a, Bgh. 



1. Central nervous system,* ^\4 . q^ ganglia cerebro-visceralia ; 



bb, pedal ganglia ; e, ganglia olfactoria proximalia ; dd^ 

 buccal ganglia ; e, gangl. gastro-wsophagal. 



2. The labial disk with the true mouth. 



8. Upper commissure of the lip-plates,* -Y-. 

 4. Elements of the lip-plate,* ^K 

 .'). Upper ends of two elements,* ^f ^. 



