EXPLANATION OF PLATES VI, VII, VIII, IX, X, XI, Xll-coutiuued. 



(paired) of the subneural areb. N. C. Neural caual. G. C. Gastric canal. 

 A. C. Arterial canal, m'^ Anterior, m- posterior muscular perforations of the 

 posterior flap. Magnified ten diameters. 



Fig. 7. — Lateral view of the entosternite of a scorpion (Buthus cjaneus 

 of Ceylon). Letters as in Fig. 5. Magnified ten diameters. 



PLATE VII. 



Fig. 1. — Section of a portion of the entosternite of a scorpion (Androc- 

 tonus funestus). Magnified 300 diameters. The preparation has been 

 stained with borax-carmine, which colours the nuclei of the cells and also, but 

 less deeply, the dense fibroid matrix, leaving the protoplasm of the cells 

 almost colourless, a. Muscular fibre attached to the entosternal tissue by 

 its sarcolemma. b. Protoplasmic corpuscles of the lacunar connective tissue 

 adjacent to the entosternite. c. Lacuna or central space of an areole of 

 the lacunar connective tissue. 



Fig. 2. Another piece of the same, in order to show transition from the 

 "fibro-niassive " to the "lacunar" variety of connective tissue, c. Lacuna 

 or central space of an areole of the lacunar connective tissue. 



Fig. 3. — Section of a portion of the entosternite of the King-crab 

 (Limulus polyphemus, Latr.). The nuclei of the cells and the surround- 

 ing matrix have taken the stain of borax-carmine, but the protoplasm of the 

 cells is unstaitied. Magnified 300 diameters. 



Fig. 4. — Section of a portion of the entosternite of a bird's-nesting spider 

 (Mygale sp.). The same treatment has been adopted and the same result 

 obtained as in the specimens Figs. 1 and 2. 



PLATE Vni. 



Fig. 1. — Section of a portion of the entosternite of Apus cancriformis, 

 showing a structure identical with that of Scorpio and Limulus figured in the 

 preceding plate, a. Nuclei of the cells, p. LTustained protoplasm of the 

 cells, c. Dense skeletal matrix. Magnified 300 diameters. 



Fig. 2. — Dorsal view of the entosternite of Apus cancriformis. Mag- 

 nified twenty-five diameters. 



Fig. 3. — Ventral view of the same. 



Fig. 4. — Blood-corpuscles of Limulus. Magnified 1000 diameters. 



Fig. 5. — Blood-corpuscles of Buthus cyaneus. abed., living ; ef, after 

 the addition of acetic acid. g. Nucleus of the same more highly magnified. 

 Excepting g, all are magnified 1000 diameters. 



Fig. 6.— Blood-corpuscles of a South African Androctonus. Drawn from 

 freshly-shed blood. 



