CRUSTACEA MALACOSTRACA. III. 49 



margins, where it is developed nearly as on the anterior segments; the corresponding coxae are armed 

 nearly as the preceding pairs. - - The thoracic legs are lost excepting the first leg in the female; this 

 leg (fig. 1 e) has been described in the diagnosis of the genus. 



Abdomen has its posterior part somewhat more produced in the male (fig. 1 h) than in the 

 female (fig. 1 f) as an oblong lobe, in the male this lobe has a few short spines on its terminal margin, 

 but whether such spines have existed in the female cannot be decided. The abdomen has one pair 

 of lateral and one pair of sublateral spines, furthermore on the dorsal surface six or seven spines of 

 varying size, and each placed on a less or more elevated foot. — The female operculum (fig. 1 g) some- 

 what longer than broad, with two pairs of small spines somewhat from the lateral margins. The 

 median lamella of the male operculum (figs. 1 h — 1 i) is scarcely three times as long as broad, broadest 

 before the middle, while the subdistal part is somewhat narrower; the end of each pleopod has a deep, 

 triangular cleft, while the major inner part forms a lobe somewhat longer than broad, which has a 

 number of long setse on the outer margin; the outer part is distinctly shorter than the lobe, and con- 

 stitutes an oblong-triangular, acute plate directed backwards and a little outwards. 



Length of the female without marsupium 3-4 mm., of the male 3-1 mm. 



Remarks. This species is so characteristic, that it may be easily recognized, though the 

 mutilated state of the specimens made the description incomplete as to several points; the worst 

 shortcoming is that nothing can be said on the strong and probably long uropods. 



Occurrence. Taken only by the "Ingolf", at a single station. 



South- West of Iceland: Stat. 78: Lat. 6o°37' N., Long. 27°52' W., 799 fath., temp. 4-5°; 1 spec. 



Dendrotion G. o. Sars. 



This very peculiar genus was established by Sars on a single species. His generic diagnosis 

 is based exclusively on the adult female, but immature females and males have the four anterior 

 thoracic segments much more slender (fig. 3 a). He said in the diagnosis: "the anterior part of the 

 mesosome rather broad, and flanked by strong spines, the posterior abruptly narrowed, with linguiform 

 produced lateral parts." But these statements are somewhat misleading and deficient. The "spines" 

 on the four anterior segments are real long and slender processes from the segments (figs. 3 a and 3 b), 

 and they are never acute as figured by Sars; the three posterior segments are produced in nearly 

 cylindrical protuberances, which are very long, excepting on seventh segment, and have the legs inserted 

 on their ends, but the coxae of these legs are produced in processes, which are of moderate length in 

 D. spinosum Sars, but in D. paradoxiun are extremely long on fifth and sixth segments, and completely 

 similar in appearance to the lateral processes of the four anterior segments, though they, as stated, 

 originate not from the segments but from the coxse. 



Remarks. Fortunately I possess not only a few specimens of D. spinosum G. O. Sars, but, 

 besides, a number of a still more curious species, so that a somewhat more full account of this type 

 can be given. 



The Ingolf-Rxpedition. III. j. 



