24 



EINAR LEA. 



[REP. OF THE "MICHAEL SARS" NORTH 



10. Leptocephalus Michael-Sarsi n. sp. 



One specimen of this species was taken at Stat. 81 

 at a depth of 150 metres. It has a length of 99 mm, 

 and as shown in fig. 1 on pi. IV, it is rather high (grea- 

 test height 13 mm). There are 52 preanal and 75 post- 

 anal segments, 127 in all. Anus is placed far forward, 



Head of L. Michael-Sarsi. 



49 mm from the point of the snout. All the fins contain 

 powerful rays. The foremost ray of the dorsal fin is 

 placed 30 mm from the point of the snout. The caudal 

 fin has 9 rays, U t having five and H 2 four. These 

 characters, in conjunction with the shape of the head 

 (see fig. 18) and the lack of teeth, denote that retrograde 

 metamorphosis has commenced. The anterior nostril is 

 tubular, with the aperture directed downwards, the post- 

 erior one a small round aperture in front of the eye. 

 There are two spots of pigment in front of the curve 

 of the alimentary canal at the pectoral fin (see fig.' 18), 

 a row of spots under the lateral line, as shown in fig. 1, 

 pi. IV, row of dots with large interspaces along the 

 anterior portion of the alimentary canal, and one or two 

 irregular elongated or round spots at the bases of all the 

 rays of the anal fin, the caudal fin and the posterior 

 rays of the dorsal fin. 



//. Leptocephalus splendens n. sp.. 



One specimen of this beautiful form was taken at 

 Stat. 45 in 150 metres. Its most conspicuous character 

 is its pigmentation, shown in fig. 2 on pi. IV, which 

 needs no further description, beyond saying that there 

 are a couple of spots on the embryonic dorsal fin directly 

 above the posterior heap of pigment at the median line. 



This larva, which is 56 mm long, and 8 mm in 

 maximum height, is not yet fully developed; there are no 

 separated nostrils, and only the caudal fin contains deve- 



loped rays. Besides distinct interspinous elements, the 

 first traces of true rays may be seen in the external 

 margin of the posterior portion of the vertical fins. The 

 interspinous elements become indistinct farther forward, 

 and directly behind the anus there is no trace of these 

 elements either. 



Rays may be seen in the pectoral fin. 



The vertical diameter of the eye is 0-8 mm, the 

 horizontal diameter 07 mm. Distance from point of 

 snout to the anterior margin of the eye is 1-2 mm. 



The mouth-opening reaches as far back as directly 

 below the centre of the eye. Snout quite pointed; point 

 of lower jaw protruding a little in front of point of snout. 



Teeth as follows: 



In each half of the upper jaw first a small "front 

 tooth", succeeded by a strong curved one, and then a 

 strong tooth and 4 very small ones. 



In each half of the lower jaw first a large curved 

 tooth, then a strong straight tooth, followed by 4 smaller 

 teeth, but larger than the corresponding teeth of the 

 upper jaw. All the teeth are directed forwards, especially 

 those of the lower jaw (see fig 19). If we look at the 

 point of the snout from above, we see that the teeth are 

 directed sideways also, and that the two big teeth in each 

 half of the upper jaw are curved inwards, having almost 

 the appearance of a thorn on a rosebush. 



There is a thickening of the alimentary canal under 

 the pectoral fin (see fig. 19), but the anterior portion is 



Fig. 19. Head of L. splendens. 



elsewhere thin ; farther back it grows thicker, forming cur- 

 ves (see fig. 2 pi. IV). The anus is placed far back, 15 

 mm from the tip of the tail. There are 135 segments, 

 81 preanal and 54 postanal. The segments are of the 

 usual form, having a dorsal angle, an angle in the lateral 

 line and a ventral angle. The only peculiarity about the 

 segments is the position of the angles, the dorsal and 

 ventral angles being placed very close to the dorsal and 

 ventral margins of the animal. 



