180 REFERENCE TO PLATES. 



PLATE 38. 



FIGURE. PAGE. 



1, 2, 4. Scurria gigantea Sowb. Original, . . . .65 



3. Scurria gigantea dentition. A. J. C., . . . 65 



5-7. Scurria gigantea (kochii Phil.). Abbild., . . .65 



PLATE 39. 



8-11. Propilidium ancyloide Forbes. Moll. Keg. Arct., . 72 



12. The same, young shell. Moll. Reg. Arct., . . .72 



13-15. Dentition and mandible of the same. Blake Rep., . 72 



16. Scurria scurra Less. Original, . . . . .62 



17. Dentition of Lepetella tubicola, 75 



18. Lepetella tubicola Verrill. Trans. Conn. Ac., . . 75 



19. Lepetella tubicola, enlarged embryonic apex, . . 75 



20. 21. Lepeta coppingeri Smith. P. Z. S., . 71 



22. Scurria mesoleuca, dentition. A. J. C., . . .61 



23, 24. Scurria scurra, enlarged apex. Original, . . 62 



25. Scurria scurra, animal. Voy. Am. Mer., . . .62 



26, 27. Scurria scurra Less. Original, . . . .62 



28, 29. Nervous system of Titiscania limacina Bergh. (See 



pi. 41.) . 164 



PLATE 40. 



29, 30. Lepeta cseca Mull. Moll. Arct. Norv., ... 68 



31. Lepeta caeca, dentition. Moll. Arct. Norv., . . .68 



32. Lepeta caeca, apex, x 4. A. J. C., . . . . . 68 



33. 34. Lepeta concentrica Midd. A. J. C., . . 69 



35. Lepeta concentrica, dentition. A. J. C., ... 69 



36, 37. Lepeta concentrica Midd. A. J. C., . . . . 69 

 38, 39. Lepeta alba Dall. Original, 70 



40. Lepeta alba Dall, dentition. A. J. C., . . . . 70 



41, 42. Pilidium fulvum Mull. F. & H., . . . .70 



43. Pilidium fulvum, dentition. Moll. Arct. Norv., . . 70 



44. Lepeta instabilis Dall. A. J. C., . 69 



45. 46. Lepeta instabilis Dall. Original, . . . .69 

 47, 48. Propilidium scabrosum Jeffr. P. Z. S., . . 73 



49. Propilidium pertenue Jeffr. P. Z. S., 



50. Propilidium compressum Jeffr. P. Z. S., ... 74 



PLATE 41. 



53-65. Titiscania limacina Bergh. Morphol. Jahrb., . . 164 



(See also pi. 39, figs. 28, 29.) 



PLATE 42. 



66-68. Acmsea marmorata T.-W. Typical. Original, . ">2 



69, 70. Acmsea marmorata var. submarmorata. Original, . 52 



