Puate 6, 
Figs. 24, 25. Argyropelecus lychnus Garman. 
Fig. 24, Axial section vertical to the median plane of the fish through an anterior lateral 
Fig. 
2 
pe 
vo. 
Fig. 26. 
Fig. 27. 
30. 
radiating organ. Stained: picrie acid-carmin. Drawing; magnified 1: 84. A, 
proximal oval part of the organ; B, zigzag fibres of the reflecting layer; C, 
constriction between the proximal and distal part of the organ; D, distal para- 
boloidal part of the organ; g, inner region; 1, middle region; p, pigment 
sheath; r, reflecting layer; s, outer region, 
The fish seen from the side. Drawing; natural size. a, anal radiating organs ; 
al, anterior lateral radiating organs; ao, anteorbital radiating organs; br, 
branchiostegal radiating organs; ml, medial lateral radiating organs ; op, oper- 
cular radiating organs; pe, pectoral radiating organs; po, postorbital radiating 
organs; ve, ventrocaudal radiating organs; ve, ventromedial radiating organs ; 
vt, ventrothoracic radiating organs. 
Figs, 26, 27. Sternoptyx obscura Garman. 
The fish seen from the side. Drawing; natural size. a, anal radiating organs ; 
al, anterior lateral radiating organs; br, branchiostegal radiating organs ; Op, 
opercular radiating organs; pl, posterior lateral radiating organs; ve, ventro- 
caudal radiating organs; ve, ventral radiating organs; vt, ventrothoracic radi- 
ating organs. 
Axial section vertical to the median plane of the fish through a ventrothoracic radi- 
ating organ. Stained: haematoxylin-picric acid-fuchsin. Drawing ; magnified 
1:42. g, inner region; gl, gelatinous tissue occupying the distal part of the 
organ; 1, middle region; p, pigment sheath; r, reflecting layer; 8, outer 
region. 
Figs. 28-30. Cyclothone acclinidens Garman. 
The fish seen from the side. Drawing; natural size. a, ventroanal radiating 
organs; ve, ventromedial radiating organs; vt, ventrothoracic radiating organs. 
The fish seen from below. Drawing; natural size. a, ventroanal radiating organs ; 
br, branchiostegal radiating organs; ve, ventromedial radiating organs; vt, 
ventrothoracic radiating organs, 
Axial section vertical to the median plane of the fish through a ventrothoracic 
radiating organ. Stained: haematoxylin-picric acid-fuchsin, Drawing; magni- 
fied 1: 520; b, blood vessel leading to the organ; c, connective-tissue capsule 
within the pigment sheath; cd, transparent connective tissue forming the super- 
ficial covering of the organ in the orifice of the pigment sheath; cr, distal part 
of the connective-tissue capsule covering the mass of radiating cells outside ; 
1, cylindrical cells of the outer zone; m, central part of the organ composed of 
small irregularly arranged polyedrical cells; p, pigment sheath; r, outer part 
of the organ composed of cells arranged in regular rows; t, transparent inter- 
mediate zone. 
