The dorsal fin. Since the dorsal profile is slightly raised at the 

 beginning of this fin, the dorsal fin occurs on a more or less distinct 

 elevation (Fig. 6; Plate II, Plate III, Fig. 1). The first ray is vertically 

 oriented above the 20th — 22nd vertebra (from the back). The dorsal 

 fin consists of 10 — 11 rays of which the 1st is the shortest, the 3rd 

 and the 4th the longest, while the subsequent ones are gradually re- 

 duced. All these rays, the last 1 — 2 excepted, are supported by long 

 narrow interneuralia. There is one free interneuralium immediately 

 before the 1st ray of this fin; moreover, 3 — 5 small narrow bones occur 

 further ahead in some specimens (157. Os., 260 Os.); these are likewise 

 regarded by the writer as free interneuralia (Fig. 6). The base of the 

 dorsal fin corresponds in length with that of 4 — 5 precaudal vertebrae. 



No paired spines — by Schultz (1938) regarded as one of the 

 generic index characters for Polyipnus Giinther — have been observed 

 before the first ray of the dorsal fin on any of the specimens available. 

 However, according to the description and illustration of P. fraseri by 

 Flower (1934) this species also lacks paired spines before the dorsal fin. 



The predorsal area — as measured from the beginning of the snout 

 to the base of the 1st dorsal fin ray — represents in 22 specimens 48 — 

 — 56 percent of the body length (without the caudal fin), 57.1 and 59.1 

 percent respectively in two other individuals, and 37.1 percent in one 

 specimen only. 



The anal fin. Position in relation to the dorsal fin varies: the 

 beginning may either be vertically oriented below the last ray of the 

 dorsal fin, or it may be slightly shifted to the front or to the rear (by 

 the length of about 2 vertebrae). The long anal fin consists of 18 — 20 

 rays, out of which only the first ten, rather strong rays, are on the whole 

 well preserved, while the subsequent rays are, owing to their fragility, 

 distinct only on very few specimens. The length of a well preserved 

 anal fin is equivalent to that of 9 — 10 caudal vertebrae. The first rays 

 are strong and long (about 5 mm), they occur below the 16th — 20th 

 vertebra (going from the end), while the subsequent ones gradually 

 grow shorter and weaker. Similarly, the first interhaemalia are the 

 longest and strongest, the subsequent ones are gradually reduced, while 

 the last extremely delicate ones, are completely obscured by the 

 accumulation of pigment in the group of anal photophores. 



The caudal fin is deeply notched, each lobe consisting of 10 cardinal 

 and 5 — 6 shorter side rays. The side rays have been preserved only 

 on some specimens. 



The luminous organs are well preserved as spots of pigment, which 

 correspond to the groups of the respective photophores. In some cases, 

 it is even possible to determine the probable number of photophores 



18 



