PLATE IV. 



an. stands for auus. 



c. 

 ca. 



'/■ 



ct. 



g.a. 

 gl. 



9t- 

 i. 



chitinous waU of the peduncle. 



caudal appendages, 



connective tissue fibres. 



connective tissue nuclei. 



cement glands. 



first and second thoracic ganglion. 



female genital aperture. 



glands of unknown function. 



thoracic ganglion. 



intestine. 



mf. stands for muscular fibres. 



n. ,, 



nuclei of the chitinogenons epithelium. 



P- 



penis. 



s. or St. ,, 



stomach. 



t. „ 



testis. 



th. „ 



thorax. 



vd. „ 



vas deferens. 



vs. „ 



vesicula seminalis. 



X. ,, 



widened portions of the oviducts near the genital 





aperture. 



I-VI. „ 



first to sixth cirrus. 



Figs. 1-7. Anatomy of the male of Scalpellum regium (Wyv. Thoms.), Hoek. 



Fig. 1. Transverse section through a male of Scalpellum regium, which is in a young 

 stage ; stomach filled almost entirely with nutritive yolk. 



Fig. 2. Section passing through the vesicula seminalis and a narrow portion of the 

 testis. 



Fig. 3. Section passing through a younger male at the level of the cement glands. 



Figs. 1-3 magnified 94 diameters. 



Fig. 4. Section of one of the cement glands ; magnified 275 diameters. 



Fig, 5. Section of the wall of a male; magnified 575 diameters. 



Fig. 6. Muscular fibres ; magnified 575 diameters. 



Fig. 7. Supposed blood-corpuscles ; magnified 575 diameters. 



Figs. 8a-8/. Six out of a series of transverse sections through the body of Scalpellum 

 calanoides, Hoek ; magnified 41 diameters, 



Fig. 9. Part of a section through the body of Scalpellum parallelogramma, Hoek, at the 

 base of the first pair of cirri ; magnified 26 diameters. 



Fig. 10. Part of a section through the body of Scalpellum nymphocola, Hoek ; magnified 

 41 diameters. 



