DESCRIPTION OF PIRATE XII. 



Fig. I. — Thick transverse section of a lobe of the hepatopancreas, unstained, mounted 

 in balsam J showing the radial arrangement of the component tubtdes, 

 X15. 



Fig. 2. — Thin stained section of one of the component tubules of the same organ, 

 X 250. The oval dark areas, of which seven are to be seen at the upper 

 part of the figure, are nuclei. The clumps of dark granules are '' zymogen." 



Fig. 3. — A longitudinal section through a portion of the same organ showing tubules 

 above and below, x 15. The section which was stained is not quite through 

 the central axis. 



Fig. 4. — Vertical section through the eye, x 250. This shows from above down, (i) 

 the thick cornea, laminated in structure ; (2.) the corneagen (somewhat 

 indistinct) ; (3) the homogeneous layer between the corneagen and the 

 upper ends of the vitrellse ; (4) the vitrellœ ; the vitrellse are surrounded by 

 dense pigment, which extends so as to partially cover the upper ends of 

 those organs. Below, and to the right of the central vitrella, a spiral pro- 

 cess of a retinula celj. can be seen joining the pigmented substratum. The 

 vitrellae appear dark in the photograph as they have taken up the orange 

 element in the stain employed (Ehrlich triple stain). 



Fig. 5. — Tangential section through nine vitreuse, showing the density of the pigment 

 between them. One ill-developed lens shows its double nature. 



Fig. 6. — Photograph of a section of the salivary gland. 



Fig. 7. — Photograph of a mature female specimen alive in a large bottle of sea-water. 

 The abdomen is raised to allow of the sweeping movements of the pleopods. 

 The first right pleopod was damaged ; it hung down helplessly in the live 

 creature ; the fourth thoracic leg of the right side was ill developed {cf. 

 plate ix) : photo by Engineer Hyndman, R.I.M. 



