PLATE Y. 
Figs. 1-27. Onchidium melctnopneumon, Bergli. 
Fig. 1. Anterior end, showing rhinophoria, frontal shield (with orifice of penis), and the oral aperture. 
Fig. 2. Posterior end of the animal (the tail turned upwards), viewed from beneath, showing anus, 
pneumostome, and (a), female genital furrow commencing at the vulva. 
Fig. 3. Bulbus pharyngeus, from the side ; a, pharynx ; b, left buccal ganglion ; c, protrusors of the 
bulbus ; d, radula-sheath. 
Fig. 4. Bulbus pharyngeus, opened on the upper side so as to show the tongue with radula (a ) ; 
b, b, palatal plates, turned backwards. 
Fig. 5. Portion of innermost part of palatal plates; a, free space between them. Cam. luc. x 55 diam. 
Fig. 6. Part of palatal plates, from the side. Cam. luc. x 350 diam. 
Fig. 7. a, First, b, second, lateral tooth. Cam. luc. x 350 diam. 
Fig. 8. Second lateral tooth, obliquely from above. Cam. luc. x 350 diam. 
Fig. 9. a, Second, b, third, c, fourth, lateral tooth, from the left side. Cam. luc. x 350 diam. 
Fig. 10. Second tooth, from the side. Cam. luc. x 350 diam. 
Fig. 1 1. Seventh tooth, from the inner side. Cam. luc. x 350 diam. 
Fig. 12. First lateral tooth, from above. Cam. luc. x 350 diam. 
Fig. 13. The same, from the outer side. Cam. luc. x 350 diam. 
Fig. 14. Outer portion of two series of teeth, from the upper side ; a, a, outermost teeth ; b, tenth ; c, 
eighth. Cam. luc. x 350 diam. 
Fig. 15. Portion of outer end of two series of teeth, from below; a, a, outermost teeth. Cam. luc. 
x 350 diam. 
Fig. 16. Part of external sixth of two series, from below ; a, a, innermost of these teeth. Cam. luc. 
x 350 diam. 
Fig. 17. Outermost tooth, from the outer side; a, cuticular folds. Cam. luc. x 350 diam. 
Fig. 18. Outermost but two, from the outer side. Cam. luc. x 350 diam. 
Fig. 19. Outermost three teeth, from behind; a, the outermost. Cam. luc. x 750 diam. 
Fig. 20. Vertical section of lung and renal organ; a, pneumostome ; b, dorsal surface. 
Fig. 21. Lamellae from third stomach, from the side. 
Fig. 22. The same, from the end. 
Fig. 23. Cuticle of second stomach. Cam. luc. x 55 diam. ( 
Fig. 24. Section of dart-gland. 
Fig. 25. Section of the ampulla of the dart-gland. 
Fig. 26. The genital mass, seen obliquely from below; a, hermaphrodite gland; b, mucous gland, 
between them the spermatheca with its duct. 
Fig. 27. The intestines from above ; a, mouth-tube ; b, bulbus pharyngeus with buccal ganglia ; c, c, 
salivary glands ; d, oesophagus ; ee, intestine ; /, anterior, g, posterior, liver ; h, ampulla 
of duct of dart-gland ; i, region of lung ; Jc, heart (inner portion of pericardium left). 
Figs. 28-31. Doriopsis nebidosa, Pease. 
Fig. 28. a, Hermaphrodite duct ; b, ampulla ; c, oviduct ; dd, prostate ; e, muscular part of vas deferens j. 
/, penis ; g, spermatheca ; h, vaginal duct ; i, vagina ; 1c, uterine duct ; l, spermatocyst. 
Fig. 29. Terminal part of vagina ; act, cuticular lining. Cam. luc. x 350 diam. 
Fig. 30. Anterior armature of vas deferens (glans). Cam. luc. x 750 diam. 
Fig. 31. Posterior armature of the same. Cam. luc. x 750 diam. 
