45 



ones scarcely different in the two sexes. Buccal mass projecting in front as a 

 sharply-pointed cone. Mandibles terminating in a lancet-like point, and having 

 inside, a flexuous lamella, by which a channel-like groove is formed, leading from 

 the tip to the base of the mandible, palp well developed, 3-articulate. Anterior 

 lip narrow, terminating in an obtusely conical point; posterior lip tapering dis- 

 tally, and slightly bifid at the tip. Anterior maxillae simple, spear-like, terminal 

 part armed with recurved teeth. Posterior maxillee wanting. Maxillipedj with 

 the basal part narrow' oblong, projecting at the end, inside, to a triangular, poinded 

 masticatory lohe, palp distinctly 3-articulate, with the terminal joint rather large, 

 lamelliform, epignath very small, rounded. 1st pair of legs powerfully developed, 

 meral joint transversely expanded, propodos large and tumefied, with the palmar 

 edge concaved, and defined behind by a small, thumb-like projection; the 2 suc- 

 ceeding pairs with the propodos much smaller, and not having the palmar edge 

 defined. 1st pair of pleopoda very large, completely covering the other pairs 

 below. Uropoda with the inner ramus rather broad, lamellar, Inarticulate, outer 

 ramus much smaller, uni-articulate, cordiform, edged with strong, ciliated setaa. 



Remarks. — This genus has been recently established by Messrs. Norman 

 and Stebbing, to include the arctic form, Anthura bracliiata of Stimpson. It is 

 very nearly allied to the genus Parcmthura Bate & Westwood, chiefly differing 

 in the facts that the flagella of both pairs of antennas are multiarticulate, and 

 that the superior ones are of the same structure in the two sexes; moreover, the uro- 

 poda exhibit a somewhat different shape. It may be noted, that in examining 

 the oral parts, I have failed to detect any traces of the posterior maxilla;, either 

 in this or the following genus, whereas in other genera belonging to this family 

 (for instance Anthura), these maxillaa are stated to exist in a rudimentary condi- 

 tion.^ The present genus contains as yet only 2 species, to be described below. 1 ) 



1. Calathura norvegiea, G. 0. Sars. 



(PI. XIX, fig. 1.) 



Paranthiira norvegiea, G. 0. Sars, Bidrag til Kundskaben om Dyrelivet paa vore Havbanker, 

 Chr. Vid. Selsk. Forh. 1872, p. 88. 



Specific Characters. — Body slender, moniliform, somewhat contracted in front 

 of the middle, with the 1st segment of mesosome rather firmly connected to the cepha- 

 lon, the 2nd, however, defined from the preceding and succeeding segments by very 

 deep constrictions. Cephalon rather small, and seen from above, rounded oval, witli 

 the side-edges evenly convex, frontal edge slightly produced in the middle. The 



a ) A 3rd species has recently been described by M. Jules Bonnier as 0. affinis. 



