312 MR WALTER E. COLLINGE ON A COLLECTION OF SLUGS. 



Plate III. 



Fig. 37. Isselentia plicata, n. sp. Generative organs. 



Fig. 38. „ ,, Distal end of penis, enlarged. 



Fig. 39. „ „ Dart, x 15. 



Fig. 40. „ „ Immature dart. 



Fig. 41. ,, ,, Head of dart, highly magnified. 



Fig. 42. „ „ Portion of immature dart, showing bends in calcareous sheath. 



Fig. 43. „ „ Diagrammatic view of fundus. 



Fig. 44. „ ,, Distal end of dart-gland showing cavity. 



Fig. 45. ,, „ Diagrammatic view of a transverse section through the distal portion of 



the dart-gland. 



Fig. 46. „ „ Longitudinal section through the proximal portion of the dart-gland. 



Fig. 47. „ „ Transverse section through the distal portion of the dart-gland. 



Fig. 48. „ „ Epithelial and gland cells from the proximal portion of the dart-gland. 



Fig. 49. ,, „ Surface view of the internal wall of the dart-gland, proximal portion. 



Fig. 50. Isselentia globosa, n. sp. Generative organs. 



