68 



KR. BONNEVIE. 



[REP. OF THE "MICHAEL SARS" NORTH 



EXPLANATION OF PLATES. 



Thecosomata PI. I— IV. 



(All figures drawn with camera lucida on dissecting microscope. 1 ) Enlargement 8 to 16 diameters). 



a 



= 



anus 



1 



= 



liver 



acc.gl 



= 



accessory glands 



oe 



= 



oesophagus 



a.n 



= 



abdominal nerve 



P 



= 



penis 



bal 



= 



balancer 



pb 



= 



proboscis 



b.m 



= 



buccal mass 



P-g 



= 



pedal ganglion 



d.l 



= 



dorsal lobe of the foot 



P-gl 



= 



pallial gland 



f 



= 



foot 



r.m 



= 



retractor muscle 



g 



= 



gill 



sh 



= 



shell" 



g-d 



= 



genital duct 



st 



= 



stomach 



g-g> 



= 



genital gland 



t 



= 



tentacles 



go 



= 



genital opening 



u 



= 



uterus 



h 



— 



heart 



u.t 



= 



unpaired tooth (stomach) 



i 



= 



intestine 



v.g 



= 



visceral ganglion 



k 



= 



kidney 



v.l 



= 



ventral lobe of the foot 



Plate I. 



Fig. 1 a-b. Peraclis diversa Mont., shell and operculum (X 8). 



2. The same, without shell, gl.l. glandular lobe of the 

 mantle margin (X 16). 



3. Procymbulia michaelsarsi, n. sp. (X 8). 



4 — 5. Limacina helicoides Jeffreys, v.bl. ventral body-lobe 



(X 16). 

 6 — 7. The same without shell; a small individual in different 



positions (X 16). 

 8 — 9. The same; fullgrown without mantle; male genital organs 



ripe; in fig. 8 seen from the dorsal, in fig. 9 from the 



right side (X 8). 



10. The same, fullgrown with young in uterus (X 8). 



11. One of the young from the uterus of the preceding 

 individual (/ 8). 



Fig. 19. The same individual as in fig. 12—13, 16 — 17, after 

 dissection (X 16). 

 20. Mpntle margin of the same individual with the gill 

 (X 16). 



Fig. 



22- 



21. 

 -23. 



24. 



25. 

 26. 

 27. 



Plate III. 



Clio cuspidata Bosc, without shell, ventral view (X 8). 



Clio pyramidata Lin., (22) ventral and (23) dorsal view. 



m mantle-margin of the right side (X 8). 



Limacina helicoides Jeffr., mantle margin with gill and 



balancer. 



Clio falcata P/eff., mantle-margin with the gill. 



Clio cuspidata Bosc, mantle margin with the gill. 



Clio pyramidata Lin., mantle-margin with the gill. 



Plate II. 



Fig. 12. Clio falcata Pfeffer, without shell, dorsal view ( / 8). 

 13. The same individual, ventral view (/ 8). 

 „ 14 — 15. Diacria trispinosa Les.. young, (14) dorsal and (15) 



ventral view (X 16). 

 „ 16—17. Clio falcata, the same individual as in fig. 12, without 



the mantle; (16) dorsal and (17) ventral view (X 16). 

 , 18. Head and foot of another individual ( < 8). 



Plate IV. 



Fig. 28. Diacria trispinosa Les., young (Cavolinia compressa) 

 (X 8). 

 „ 29—32 and 34. The same. Individuals showing the gradual 

 increase of the soft body and of the pigmentation of 

 the shell (X 8). 

 33. Soft parts of the stage shown in fig. 31 (X 16). 



l ) Fig. 24 — 27 on compound microscope. 



