296 Dr. J. Vosseler on the 



and in this I htave been aided by the kindness of Prof. Jules 

 Eichard^ of Paris, to whom I am indebted for correctly deter- 

 mined specimens of this species, which would be difficult to 

 recognize from Lilljeborg's description. 



The slender ovate thorax is not strikingly distinguished 

 from the short abdomen. The lateral angles of the fourth 

 segment are not produced. The first antenna extend the 

 whole length of the body and are very strongly constructed, 

 by no means slender. Lilljeborg's statements as to the geni- 

 culate male antenna, namely " articulus antepenultimus plane 

 dearmatus," I do not find to be correct. In my investiga- 

 tions 1 always found seated npon the joint in question two 

 seta3, one of which is very long. 



The following numbers show the compai-ative lengths of 

 the individual joints in the female antennge : — 



I. II. III. IV. V. Yl. Yll. VIII, IX. X. XI. XII. Xin. XIV. 



30. 25. 15. 12. 18. 18. 20. 18. 18. 18. 20. 13. 25. 15. 



The mandibles are armed with six distinct teeth, besides 

 which there are towards the emargination some rudimentary 

 ones. The inferior maxilliped is more stumpy than in D. 

 gracilis^ Sars. Its first joint lias, on the anterior margin, 

 four ridges, of which the first bears one seta. On the second 

 there are two, on the third three, of which the middle one is 

 the shortest, and on the fourth four set^e. One of the most 

 important characters of this species, as in the other species of 

 the genus ViaptoviuSy is furnished by the structure of the 

 rudimentary pair of feet. The rudimentary foot of the female 

 consists of a short basal joint upon which are seated a two- 

 jointed outer and a one-jointed inner ramus. The first joint 

 of the outer branch is long ; the second cleft at the apex into 

 two dissimilar parts. Of these the inner one forms a spine 

 bent inwards ; the tip of the other bears a short and a long 

 seta, the latter extending as far as the end of the above- 

 mentioned spine. Opposite the base of the spine on the outer 

 side of the joint there is a fine setule. The inner ramus is 

 longer than the first joint of the outer one and furnished at 

 the end with two setse of nearly equal length, besides which 

 there is a smaller one seated more towards the inner side. 

 The right rudimentary foot of the male consists of a basal 

 joint which is but little longer than broad. The first joint of 

 the outer ramus is short and produced into a small projection 

 on the outer margin. Tlie second joint is about as long as 



