536 F. M. MacFaArtanp, The nudibranch family Dironidae. 
Fig. 15. First lateral tooth ventral view, the denticles concealed by 
the base. 220: 1. 
Fig. 16. First lateral tooth ventral view, the denticles visible. 220:1. 
Fig. 17. Outer face mandible. ww wing portion. sm masticatory 
portion. A hinge ligament. 12:1. 
Fig. 18. Inner face mandible. w wing portion. m masticatory sur- 
face. h hinge ligament. ce chitinous band connecting the mandibles 12:1. 
Fig. 19. Second lateral tooth, outer face. 220:1. 
Bilfatter32 
Fig. 20. Reproductive system of Dirona pieta MAcF. The ducts 
have been spread out from their natural position to show their relations 
with each other. ov. ft ovotestis. h.d hermaphroditic duct. h.a herma- 
phroditic ampulla. x point of division of hermaphroditice duct into 
the oviduct, and v. d the vas deferens.. 7» preputium. m retractor 
muscle of preputium and glans. «a atrium, receiving on its dorsal surface 
the duct of s the spermatotheca. «a albumen gland. n mucus gland. 
lapsık 
Fig. 21. Left Rhinophore of Dirona albolineata MAcF. from behind 
and within. 9:1. 
Fig. 22. Rinophore of Dirona pieta MAcF. from in front. 9:1. 
Fig. 23. Clavus of Rhinophore of Dirona piela MACF. from behind. 9:1. 
Fig. 24. Central nervous system of Dirona pieta MacF. in dorsal 
view. c cerebral, pl pleural portions of cerebro-pleural ganglia. » pedal 
ganglia. r. g rhinophore ganglia. c. I rhinophore nerve. c 2 second cere- 
bral nerve, to mouth region and veil. c 3 third cerebral nerve, to mouth 
region and veil. c4 fourth cerebral nerve. c5 optie nerve, arising 
from the minute optie ganglion. e eye. c-b.c cerebro-buccal connectives. 
pl.1 first pleural nerve. pl. 2 second pleural nerve. p]1 first pedal nerve. 
p 2 second pedal nerve. p third pedal nerve. ».p.c parapedal commis- 
sure. p.c pedal commissure. pl. c pleural, or visceral commissure. n.g geni- 
tal nerve; to its left the paired visceral nerves arising from the same 
commissure. D. buccal ganglia, removed from their normal position 
below the cerebral ganglia. b. c buccal commissure. The otic vesicle is 
seen close to the side of the cerebro-pleural ganglion, resting upon the 
antero-dorsal surface of the pedal ganglion. 28:1. 
