No. 3.] STUDY OF STENOSTOMA LEUCOPS O. SCHM. 303 



EXPLANATION OF PLATES. 



Fig. I. Stenostoma leucops. Leitz, obj. 7, oc. i. 



Fig. 2. The integument from a longitudinal section of a worm which was fixed in 

 chrom-osmic-acetic acid and lightly stained in hcematoxylin. Spencer yL hom. imm. 

 obj. and Leitz oc. 3. 



Fig. 3. Parenchyme from a longitudinal section of a worm which was fixed in 

 corrosive sublimate and stained in hematoxylin. Spencer j^ hom. imm. obj. and 

 Leitz oc. 3. 



Fig. 4. Parenchyme from a longitudinal section of a worm which was fixed in 

 chrom-osmic-acetic acid and stained with hsematoxylin. Spencer -^^ hom. imm. obj. 

 and Leitz oc. 3. 



Fig. 5. Pharynx and cone-shaped depression of the integument from a sagittal 

 section of a worm which was fixed in chrom-osmic-acetic acid and stained in hema- 

 toxylin. Spencer ^ hom. imm. obj. and Leitz oc. i. 



Pig. 6. Cross-section of the pharynx from a section of a worm which was fixed 

 in corrosive sublimate and stained in haematoxylin. Spencer -^-^ hom. imm. obj. and 

 Leitz oc. 3. 



Fig. 7. Pharyngeal cell from a longitudinal section of a worm which was fixed in 

 chrom-osmic-acetic acid and stained in alum carmine. Spencer j^ hom. imm. ol)j. 

 and Leitz oc. 3. 



Fig. 8. A part of a sagittal section showing the muscle cells connecting the 

 ventral wall of the pharynx with the ventral body wall. The section is from a 

 worm which was fixed in chrom-osmic-acetic acid and stained in alum carmine. 

 The cilia of the epithelial cells of the pharynx are matted into a dense mass which 

 took a dark red stain. Spencer ^^ hom. imm. obj. and Leitz oc. 3. 



Fig. 9. The wall of the intestine from a longitudinal section of a worm which 

 was fixed in chrom-osmic-acetic acid and stained in alum carmine. Spencer ^^ hom. 

 imm. obj. and Leitz oc. 3. 



Fig. 10, Epithelial cells of the intestine which were crushed from the living worm. 

 Spencer \ obj. and Leitz oc. 3. 



Fig. II. Epithelial cells of the intestine which are filled with oil-globules from a 

 cross-section of a worm which was fixed in chrom-osmic-acetic acid and stained in 

 haematoxylin. Spencer -^^ hom. imm. obj. and Leitz oc. 3. 



Fig. 1 2. Same as above from a worm which was fixed in chrom-osmic-acetic acid 

 and stained in picro-carminate of soda. Spencer ^-^ hom. imm. obj. and Leitz oc. 3. 



Fig. 13. Diagram of the water vascular system. 



Fig. 14. Longitudinal section of the ventral limb of the water vascular tube from 

 a section of a worm which was fixed in corrosive sublimate and stained in hsematoxy- 

 lin. Spencer ^^ hom. imm. obj. and Leitz oc. 3. 



Fig. 15. Cross-section of the ventral limb of the water vascular tube from a sec- 

 tion of a worm which was fixed in corrosive sublimate and stained in hcematoxylin. 

 Spencer ^-^ hom. imm. obj. and Leitz oc. 3. 



Fig. 16. Diagram of the brain. 



Fig. 17. Cross-section of the brain commissure from a section of a worm which 

 was fixed in chrom-osmic-acetic acid and stained in alum carmine. Spencer ^-^ hom. 

 imm. obj. and Leitz oc. 3. 



Fig. 18. Cross-section of one lobe of the brain, together with a longitudinal sec- 

 tion of one-half of the commissure taken in a plane running llirough the centre t,f 



