100 



peduncle. Epignath of the maxillipeds with the outer edge angular in the middle. 

 1st pair of legs with the carpus about the length of the 2 preceding joints com- 

 bined, and armed inside with 18 — 20 spines; dactylar claws in all pairs nearly 

 equal. Middle piece of male operculum not expanded at the end, which is qua- 

 drilobate. Uropoda exceeding in length the caudal segment, basal part rather 

 elongated, though not quite as long as the inner ramus, outer ramus somewhat 

 smaller than the inner, both being linear in form. Colour yellowish, densely 

 mottled with reddish brown specks. Length of adult female 7 mm., of male 10 mm. 



Remarks. — This is the first described species of the genus, and is easily 

 recognizable from the other as yet known forms, by the form of the cephalon and 

 the armature of the caudal segment. The Henopomus muticas of Kroyer is un- 

 doubtedly identical with the form here treated off. 



Occurrence. — This species occurs along the whole Norwegian coast, from 

 the Christiania Fjord to Vadso, and is generally found in depths ranging from 

 30 to 100 fathoms, on a rocky bottom, overgrown with Hydroida and Polyzoa. 

 It is rather brittle, and therefore difficult to preserve in a perfect state. The 

 long inferior antenna and the uropoda are especially liable to be broken or de- 

 tached from -the body, when the animal is put in alcohol. 



Distribution.— British Isles (Sp. Bate), Kattegat (Meinert), Dutch coast 

 (Hoek), coast of France (Bonnier), Greenland (Hansen). 



Gen. 2. Ianthe, Bovallius, 1881. 



Generic Characters. — General form of body as in Ianira. Cephalon with 

 a strong rostral projection, and having the lateral parts produced to very pro- 

 minent, acute lappets. Segments of mesosome with the lateral parts laciniate, 

 and produced so as wholly to cover the coxal plates. Caudal segment forming 

 at the end, on each side, a triangular expansion. Antennae about as in Ianira, 

 except that the inferior ones are comparatively less elongated. Epignath of 

 maxillipeds simple lanceolate, outer edge not angular. Oral parts otherwise, as 

 also the legs and appendages of metasome, nearly as in Ianira. 



Remarks. — This genus was established in the year 1881 by Dr. Bovallius, 

 to include a supposed new species from Baffin's Bay, I speciosa, which, however, 

 in the opinion of Dr. Hansen, is not specifically distinguishable from Ianira 

 sjrinosa of Harger. The genus agrees very closely in almost all anatomical details 



