H 



CRUSTACEA MALACOSTRACA. III. 



towards the end (PI. I, fig. 4 b), directed inwards and distinctly forwards, and with the end cut off 

 transversely. The maxillipeds (PI. I, fig. 4 c) have the second joint of the "palp" about as broad as the 

 lobe from the second joint — the preecoxa, a, not counted — ; the epipod is much longer than broad. — 

 First pair of thoracic legs (PI. I, figs. 4 f — 4 g) somewhat shorter than the second, similar in both sexes 

 and built as a kind of prehensile organ, as the fifth joint is considerably thickened, with a number of 

 spines arranged along both sides near the lower margin, while the sixth joint is about two-thirds as long 

 as the fifth, with a very close row of extremely small spines along the prehensile margin. All thoracic 

 legs with the seventh joint short, the claw strong and moderately short, the accessory claw well developed, 

 strong. — In the males the median lamella of the operculum is moderately broad at the base, nar- 

 rowing considerably towards the middle and widening a little or moderately towards the posterior end. 

 Female operculum not produced backwards, with the median part of the hind margin nearly transverse, 

 or even a little concave. — Uropods from somewhat shorter to somewhat longer than the abdomen; 

 peduncle and rami well developed, spiny. 



By these characters combined the genus is sharply defined from Ianiropsis G. O. S., Acantha- 

 spidea Stebb., Janirella Bonn, and other genera. The most interesting characters for species and for 

 sections of species are found in the development of epimeral processes or plates from the basal joint 

 of the thoracic legs; such epimeral processes or plates are visible from above, and take part in shaping 

 the outline of the thorax. It may be useful to give a tabular view of these characters in the seven 

 species found in the "Ingoif" area. 



A. Epimeral plates developed at all thoracic segments. The plates are small, never produced into 

 long, acute processes, but bifid at two or three of the segments. 



1. I. maculosa Leach. 2. / alia Stimp. 3. / fricornis Kr. 



B. Epimeral plates completely wanting 4. I. pulchra n. sp. 



C. Epimeral plates developed at the three posterior segments, but wanting at least at second and 



third segments. 



a. At first segment a long, narrow epimeral process; between the two lamellar processes of fourth 

 segment a small, narrow epimeral process 5. I. laciniata G. O. S. 



b. No epimeral process at first segment; sometimes a minute epimeral tubercle between the two 

 lamellar processes of fourth segment 6. I. VilhelmincB Steph. 7. I. spinosa Harg. 



2. Ianira maculosa Leach. 

 (PI. I, figs. 1 a— if.) 

 1814. Ianira maculosa Leach, Edinb. Encycl. VII, p. 434. 

 ?i846. Henopoinns muticus Kroyer, in Gaimard, Voy. en Scand. Crust; PI. 30, figs. 1 a — in. 



1847. Kroyer, Nat. Tidsskr., Ny Rsekke, Vol. II, p. 366. 



! 1897. Ianira maculosa G. O. Sars, Account, II, p. 99; PI. 40. 



This species, which at the Faeroes has been taken in 6 fathoms, and goes down not only to 

 considerable depths but even to about 1100 fathoms (see later on), shows considerable variation according 

 to the depth where the specimens lived. .Specimens taken in depths to nearly 100 fathoms are mottled, 



