18 



the genus Paratanais. Inferior antennae, as a ride, rather narrow, with the 2nd 

 joint more or less dilated. Mandibles well-developed, cutting edge obscurely 

 dentated and provided on the left mandible with a distinct secondary lamella, 

 molar expansion cylindric, straight, and slightly dilated at the tip, which is 

 transversely truncated, and surrounded with dentiform tubercles. Oral parts in 

 male, excepting the maxillipeds, abortive ; epistome prominent, globular. Chelipeds 

 in female less robust, generally attenuated distally, with the hand comparatively 

 narrow, and the fingers simple; those in male but slightly different. 1st pair 

 of pereiopoda, as a rule, longer than the second, with the dactylus setiform; the 

 succeeding ones comparatively short, basal joint of the 3 posterior pairs generally 

 strongly tumefied. Pleopoda normally developed and larger in male than in 

 female. Uropoda short, biramose, both rami Particulate, or one of them 

 uniarticulate. Incubatory pouch normal. 



Remarks. — This genus is chiefly distinguished from the preceding ones 

 by the total absence of eyes and ocular lobes, as also by the somewhat different 

 structure of the mandibles. Moreover the subulate form of the superior antennae 

 in the female, and the narrowness of the hand of the chelipeds may serve as 

 recognizing marks. The genus contains rather a large number of species, which 

 all are true deep-water forms, and pronouncedly tubicolar, constructing small 

 cylindric tubes of mud-particles agglutinated together. No less than 9 different 

 species occur off the coast of Norway, and will be described below. Moreover 

 the present author has recorded a, Mediterranean species, T. messinensis, and 2 

 additional species, T. hergvMensis and T. braehyurus have been described by 

 Mr. F. Beddard from the Challenger Expedition. 



1. Typhlotanais tenuimanus (Lilljeb.). 



(PI. VIII, fig 1.) 



Tanais tenuimanus, Lilljeborg, Bidrag till Karmedomen om de inom Sverige och Norrige fore- 



kommande Cvustaceerne af Tanaidernes familj, p. 15. 



Specific Characters. — 9- Body more than 6 times as long as it is broad, 

 with the segments only separated by very narrow constrictions. Cephalosome rather 

 large, much longer than it is broad, and gradually attenuated in front. 1st 

 free segment of mesosome much shorter than the others, the 4 succeeding ones 

 subequal, rectangular, last one somewhat shorter. Metasome slightly dilated in 

 the middle, with the terminal segment about the length of the 2 preceding ones 

 combined. Superior antennas but little shorter than the cephalosome, subulate, 

 terminal joint much elongated and narrow, almost attaining the length of the 



