34 



EINAR LEA. 



[REP. OF THE "MICHAEL SARS" NORTH 



has a curved tooth anteriorly, then 4 big straight teeth 

 and after an interspace 3 small straight ones. 



The nostrils are represented by a triangular groove 

 near the eye. 



The point of the notochord is tilted upward very 

 slightly; Hj and H 2 feebly developed and situated under 

 the point of the notochord. 



As for pigment there are only a few faint dots near 

 the tip of the tail under the lateral line. 



The measurements and number of segments are shown 

 in the following table: 



Smaller 

 specimen 



Total length 



Distance from point of snout to anus 



Greatest height 



Length of head 



Distance from point of snout to foremost 



margin of eye 



Vertical (and maximum) diameter of eye 



Number of preanal myomeres 



of postanal „ 



Total number of myomeres 



28 r 

 25 



4 



3-4 



1-6 

 0-7 



ca. 



118 



32 



150 



Larger 

 specimen 



31 mm 



27 „ 

 4 . 

 3-2 , 



1-6 „ 



0-7 , 



119 



ca. 30 



. 149 



If we look at the table on pp. 6—7 giving the number 

 of vertebrae in various eels we shall see that the two 

 larvae in question may be the larvae of either Synapho- 

 branchus pinnatus or Serrivomer Beani. The Leptoce- 

 phalus of the former being well known, Serrivomer is, 

 in the present state of our knowledge, the only alter- 

 native. Pending the possible discovery of more fully 

 developed larvae, those just described are, in the meantime, 

 named L. megacara. 



22 — 24. Three very small larvae from 

 the Sargosso Sea. 



Three very small larvae, probably belonging to three 

 different species, represented in pi. VI, figs. 2 — 4, were 

 taken at Stat. 64. It is impossible to identify them with 

 known species of Leptocephali, and they are too feebly 

 developed to serve as types for new species, so I shall 

 call them merely nos. 1, 2 and 3. 



Larva no. 1 is rather high relatively to length, thus 

 resembling the larva of the common eel, but the number 

 of segments exceeds 130, according to an approximate 

 estimation. Length about 17 mm, greatest height 2-4 mm, 

 anus 15 mm from point of snout. Head 2-1 mm long, 

 length of snout 0-9 mm, and greatest diameter of eye 

 0-6 mm. The pigment consists of some dots along the 



notochord near the tip of the tail. The embryonic pec- 

 toral fin presents itself as a little flap. 



Larva no. 2 greatly resembles the larva of Conger 

 vulgaris, figured by Schmidt (29); from the number of 

 segments (between 150 and 160) it might possibly be a 

 small larva of Conger vulgaris, but it differs in having 

 the anus nearer the tip of the tail; perhaps it is a "pre- 

 larva" of L. enchodon (p. 25). This larva is more slender 

 than no. 1; it measures 17 mm in length, greatest height 

 1-8 mm; the anus lies about 15 mm from the point of 

 the snout; length of head 1-9 mm; length of snout 0-9 mm; 

 greatest diameter of the eye 0-5 mm; pigmentation agrees 

 with that of no. 1 (pi. VI fig. 3); embryonic pectoral 

 fin present. 



Larva no. 3 is somewhat larger, being 21 mm long 

 and attaining a maximum height of 2-2 mm. It is badly 

 preserved, so that the number of segments cannot be 

 accurately determined. It seems to have more than 120 

 segments, however, and doubtless does not belong to 

 Angullla vulgaris. It bears a great likeness to larva no. 2, 

 but differs fn having a longer snout, and an oval contour of 

 the eye. The anus is placed about 18 mm from the point of 

 the snout; length of head 2-3 mm, of snout 1-0 mm; grea- 

 test diameter of the eye 0-6 mm; pigmentation like that 

 of no. 2 (see fig. 4 pi. VI); embryonic pectoral fin present. 



Larva no. 1 was taken in the net at 100 metres, 

 no. 2 at 50 metres, and no. 3 at 300 metres; from their 

 size it may be concluded that they cannot have pro- 

 gressed far from the spawning place. 



25. Leptocephalus mysticus n. sp. 



This larva, which I propose to call L. mysticus was 

 taken at Stat. 53 in the net at 1300 metres. Its meta- 

 morphosis has begun, but if not abnormally developed, 

 the transformation of this species must differ from that 

 of, for instance, Angullla vulgaris since the appearance 

 of pigment in Anguilla occur very late in the meta- 

 morphosis, whereas this larva is abundantly pigmented 

 though its body is still high and compressed. It is shown 

 in fig. 7 pi. V and its peculiar aspect is due to the fact 

 that the head and the lower portion of the body from the 

 lateral line downwards are abundantly pigmented, while 

 the greater part of the dorsal portion is entirely without 

 pigment, so that the muscle-segments become visible as 

 in other leptocephalids. 



The animal is high in proportion to its length (80 mm), 

 and the segments of the body are curved without sharp 

 dorsal and ventral angles. At the junction of the head 

 and trunk a rather acute angle is formed between the 

 dorsal contour of the head and body, similar to that in 

 Hyoprorus messinensis. 



