J22 CRUSTACEA MALACOvSTRACA. II. 



incisive margin of the right mandible has few and obtuse teeth, while that of the left mandible is 

 somewhat incised and the movable lobe moderately developed. The maxilhilse are very slender (fig. 3e); 

 the maxillipeds (fig. 3f) have their proximal unpaired part long, the lobes are well separated to their 

 base and each has two short setje at the terminal margin. 



The thoracic segments have the lateral margins conspicuously angular and the anterior seg- 

 ments as to length developed as in Leptognathia. The thoracic legs shaped as in the last-named genus. 



Abdomen in the female very short (figs. 3a and 4a); its five anterior segments combined at 

 most as long as seventh thoracic segment, considerably narrower than this segment and somewhat 

 narrower than sixth abdominal segment, which is broader than long and posteriorly somewhat pro- 

 duced. Pleopods wanting. Uropods short, with the exopod either unjointed or not marked off, the 

 endopod one-jointed or two-jointed. — In the subadnlt male the five anterior abdominal segments are 

 somewhat longer than in the female and their pleopods are moderately long, but terminal setae are 

 either somewhat short (fig. 3m) or quite wanting (fig. 5 c). — (Adult males unknown). 



Remarks. This genus differs from all preceding genera with four-jointed antennulse in having 

 the five anterior abdominal segments much reduced both in length and breadth; in the female of the 

 genus Anarthriira G. O. S. the abdomen is also much reduced in length, but all segments are fused 

 so that not even a vestige of a division into segments is visible. Furthermore, in Anarthnira the 

 coxal joint of the chelipeds is, according to Sars' figure, developed as a free, outstanding joint different 

 from the structure found in any species of Paranarthrura. Finally, the abdomen in the subadult male 

 of Anarthriira is according to Sars much more developed than in Paranarthrura (I consider the male 

 of Anarthrnra figured by Sars to be not adult but in all probabilit}' only subadult, because its anten- 

 nulae contain only five joints as in subadult males of several species of Leptognathia^ and because the 

 thoracic segments and their legs do not differ materially from those in the female.) 



Three new species secured by the "lugolf in the warm area are referred to this new genus. 

 These species differ materially from each other in several particulars. 



76. Paranarthrura insignis n. sp. 

 (PI. XII, fig.s. 3 a -3 m.) 



Female. Moderately slender (fig. 3a), almost seven times as long as the breadth of the cara- 

 pace somewhat before its hind margin and tapering considerably backwards. — tarapace large, as 

 long as the two following segments combined (fig. 3 a), somewhat longer than broad, somewhat behind 

 the middle more than two and a half times as broad as at the insertion of the antennulse and thus 

 nearly pear-shaped. 



Antennulee a little or somewhat shorter than the carapace, rather slender (fig. 3 b). First joint 

 uncommonly long, somewhat longer than the three other joints combined, nearly three and a half 

 times as long as deep, but considerably deeper somewhat from the base than somewhat beyond the 

 middle. Second joint distinctly produced above, as deep as the distal part of the first joint but slightly 

 more than one-third as long as that joint; third joint distinctly longer than deep; fourth joint some- 

 what shorter than the second. — Antenna; .slender and moderatch short. 



