PLATE VI. 



A. (in fig. 1) stands for matured ovum. 

 A. (in fig. 3) ,, body-cavity. 



A. (in fig. 6) ,, musculus adductor scutorum. 



B. stands for ovum, not fully matured. 



C. (in fig. 1 ) stands for young ovarian eggs. 



C. (in fig. 10) ,, outer sac of connective tissue. 



c. stands for inner layer of longitudinal muscular fibres. 



D. ,, genital duct. 



d. (in fig. 1) stands for epithelium of ovarian wall. 

 d. (in fig. 3) ,, cement ducts. 



gl. stands for pancreatic gland. 



OS. or G. suprao?sophageal ganglia. 



OA. ,, genital aperture. 



L. „ labrum. 



I. , , ccEca of the so-called liver. 



M. , , mouth. 



0. stands for ovarian coeoa. 

 oc. „ eye. 

 Od. or ov. oviduct. 

 Oe. , , oesophagus. 

 o.n. „ four optic nerves. 

 P. ,, pancreatic gland. 



p.n. ,, peduncular nerve. 

 S- (in figs. 4 and 6) stands for stomach. 

 S. (in fig. 10) stands for funnel at the end of the oviduct. 

 S'. stands for curious sac. 

 (. ,, testicular cosca. 



JV. , , body -wall. 

 X. (in fig. 2) stands for yolk-elements of egg. 

 X. (in figs. 10 and 11) stands for unknown mass. 

 I.-IIl. stands for small optical ganglia. 



Fig. 1. Part of one of the coeca of the ovarium of Scalpellum vulgare, Leach ; magnified 

 685 diameters. 



Fig. 2. Nucleus with nucleolus of a nearly ripe ovarian egg of Scalpellum vulgare. 

 Leach ; magnified 685 diameters. 



Fig. 3. Part of a section of the peduncle of Scalpellum regium (Wyv. Thorns.), Hoek^ 

 in its lower half ; magnified 33 diameters. Body-cavity, acting as the main 

 cement duct. 



Figs. 4, 5. Pancreatic gland of Scalpellum, parallelogramma, Hoek. 



Fig. 4. Part of a transverse section through the cephalic part of the body ; magnified 33 

 diameters. 



Fig. 5. Section of the gland where it has its greatest diameter; magnified 106 

 diameters. 



Fig. 6-9. Anatomy of Lepas anatifera, Linnd 



Fig. 3. Sagittal section of the body ; magnified 1 "5 diameters. 



Fig. 7. Lateral view of the upper and front part of the stomach, after the muscles have 

 been removed ; magnified 8 diameters. 



Fig. 8. Frontal view of a part of the stomach with the supracesophageal ganglia ; 

 magnified 8 diameters. 



Fig. 9. The eye and its innervation ; magnified 58 diameters. 



Fig. 10. The apparatus by means of which the oviduct opens in Scalpellum tyulgare, 

 Leach ; magnified 106 diameters. 



iFig. 11. Same apparatus oi Lepas hillii, Leach; magnified 58 diameters. 



