CRUSTACEA MAIACOSTRACA. IV. 



Occurrence : Taken by the "Ingolf" at a single station. 



West of Iceland: Stat. 8: Lat. 63°56'N., Long. 24^0' W., 136 fath., temp. 6.0°; 1 specimen. 



Distribution. The type was secured West of Ireland in 382 fath. (Caiman). 



Besides gathered at several places near Capri in depths from 53 to 584 fath. (Caiman). 



4. Leucon spinulosus n. sp. 



(PI. I, rigs. 1 a— id.) 



Female (with marsupium). Carapace moderately oblong (fig. 1 a), with pseudorostrum not in- 

 cluded about one-third as long again as deep, and about as long as the free segments combined ; when the 

 pseudorostrum is included the carapace is a little less than twice as long as deep. The serration on the dorsal 

 edge is found only on its anterior third or fourth; as a rule 3 rather long teeth are seen in front, then comes 

 an interruption, and behind it 2 to 5 small teeth; a few teeth are found on each side between the antennal 

 notch and the frontal lobe; the latter has no lateral tooth (fig. 1 b). Pseudorostrum is rather long, somewhat 

 less than half as long as the carapace, more than twice as long as deep at the base, and very moderately 

 upturned, with the proximal part of the upper margin a little convex; about the proximal half of its upper 

 side has 4 to 7 teeth, but these show much individual variation in size, being sometimes all long, sometimes 

 rather or very small, or some large and others small. The lower margin of the pseudorostrum is oblique but 

 not concave as in L. siphonatus Calm., with a couple of smaller teeth near the middle. The antennal notch 

 is very distinct and varies in shape, generally with a small tooth on its upper margin; the front margin above 

 the notch generally with 2 or 3 long teeth and above them frequently 2 small teeth. The lower margin of the 

 carapace is serrated in nearly its whole length, and the anterior teeth are long and strong; in front the margin 

 curves upwards to the antennal notch, below which a good-sized tooth is seen, while the tooth on the middle 

 of the curvature is also large. 



Second and third free segments each with the anterior margin down to the middle of the sides armed 

 with irregular, somewhat small teeth; furthermore the upper front angle of first segment has a couple of 

 teeth ; the upper margin of fourth segment with 2 teeth ; finally 2 teeth just above the coxa of third leg on 

 the anterior margin of the segment, and a single tooth far downwards on the front margin of second seg- 

 ment; in immature specimens some or many of the teeth on the free segments are apparently wanting. Ab- 

 domen slender and decidedly longer than eephalothorax with pseudorostrum. 



The branchial siphon is almost or fully as long as the free thoracic segments combined. The antennulae 

 fig. 1 a) are well developed; second joint of the peduncle twice as thick as, and slightly longer than, third 

 joint, which is as long as the outer flagellum, while the inner flagellum is about as long as first joint of the outer. 

 (First pair of legs mutilated in my specimens). Second pair of legs (fig. 1 c) most characteristic; the caqms 

 is slender and very long, three times as long as the thick merus and considerably longer than the two distal 

 joints combined; the terminal joint is very slender, with some very long seta? at the end. -- The uropods 

 are rather long, somewhat longer than the two distal abdominal segments combined; the peduncle in the 

 adults a little longer, in younger specimens (fig. 1 d) a little shorter, than first joint of the endopod, with only 

 2 spines on the inner margin; first joint of the endopod a little more than two and a half times as long as 



