PLATE LXXIT. 



Figs. 34-41. Opostomian mieripints. 



Fig. 34. Median section of ,a lenticular white dorsal phosphorescent organ, x 80. 



Fig. 35. Median section of another lenticular organ, showing incipient fission, x 80. 



Fig. 36. Transverse section of the distal part of the anterior ray of the pectoral fin, whicli is prolonged 

 to form a liarbel. x 100. 



Fig. 37. Median section of a hemispherical white dorsal phosphorescent organ, x 80. 



Fig. 38. Median section of a black dorsal phosphorescent organ, x 80. 



Fig. 39. Head in profile, from a spirit .specimen : natural size. 



a. Dorsal phosphorescent organs (simple) ; h, superior lateral line of compound phosphorescent organs ; 

 c, inferior lateral line of compound phosphorescent organs ; d, suborbital phosphorescent organ ; 

 e, barbel attached to lower jaw ; /, barbels formed by the first ray of the pectoi'al fins. 



Fig. 40. Longitudinal .section of the suborbital phosphorescent organ. x 100. 



a, Outer skin ; h. external radially striped part ; c, gland-tubes : rf. iiervus phosphorius. 



Fig. 41. Section of the suborbital phosphorescent organ. Portion of the external radially striped part, 

 shown in fig. 40. x 800. 



II, Gland-tubes of the interior ; //, membrane ilividing the outer layer from the Inner glandular part ; 

 c, layer of ganglion cells ; </, ]ihosphorescent cells; c, long and slender cylindrical supporting cells 

 between them : /. outer surface. 



Fig. 42. Echiosfoma hnrliafnm. 



Fig. 42. The brain in profile. x 4. 



'«, Spinal cord ; b, and c, cerebral nerves ; d, nervus acusticus ; c, nervus trigeminus ; /, nervus facialis 

 g, nervus phosphorus (part of the trigeminus) ; h, nervus oculomotorius ; K. nervus opticus ; /, 

 nervus olfactorius : k. cerebellum; I, lobus opticus ; Hi. lobns phosphorius. 



Figs. 43, 44. Scopeltis hmoiti. 



Fig. 43. Vertical section of the single compound dorsal phosphorescent organ shown in fig. 44. 

 X 1000. 



a, Long and slender peduncle of the phosphorescent cell ; h, nucleus of the phosphorescent cell ; c , large 

 oval vacuole outside the nucleus ; d, slender cylindrical supporting cells ; e, grauular ceDs with 

 indistinct outlines(gangIion cells): /.very distinct nui'lei of the ganglion cells; (/, outer surface clothed 

 with fl.it epithelium. 



Fig. 44. Vertical section of the exposed part of tlie single compound dorsal phosphorescent organ. 



X 80. 



", Outer surface with flat epithelial cells; b, granular mass of ganglion cells, with distinct nuclei; c, 

 phosphorescent cells ; d, reflecting layer of spicules ; c, blood-vessels extending up into the masses of 

 phosphorescent cells; /, nerves extending downwards from the external ganglion cell layer : ij, layer 

 of tissue with numerous blood-vessels : h, pigment coat. 



