84 



longitudinal furrows, like also the merus, and there is one furrow on the carpus. These grooves 

 are not observed in Scyll. Martoisii. The 4"^ and the 5"^ legs are likewise a little stouter 

 and are also furrowed on their outer surface. 



The abdominal appendages of the 2""^ somite (those of the 1=' are wanting) are biramous, 

 the rami equally long, foliaceous, though still narrow; the exopodite is a little broader than 

 the endopodite, that carries on its inner margin a stylamblys, 0,08 mm. long and half as thick, 

 finger-shaped and situated just in the middle of the endopodite. The pleopods of the 3 following- 

 somites are biramous; one of the two rami is 1,3 mm. long, spatulate, the widened part 0,45 mm. 

 broad, obtusely pointed and fringed with plumose setae, the other 3-jointed ramus is not yet 

 fully developed, only half as long as the other and tapers to its extremity. 



This specimen presents a uniform yellowish colour; the smooth, underlying part of the 

 i^' abdominal tergum is marked with a dark fleck in the middle, nearly as in Scyll. sordichis, 

 but less distinctly defined and a dark fleck exists also near the inner border of the distal 

 antennal squame. 



Scvll. biciispidatjis is also closely allied to Scyll. ciiltrifcr (Ortm.) = Scyll. sordidns of 

 the Report on the Challenger Macrura, in which the carapace appears likewise bicuspidate in 

 the middle line. Scyll. ailtrifcr, however, differs at first sight by the subchelate shape of the 

 3'''^ pair of legs and also by the following, when the figures in the Challenger Report are indeed 

 accurate. The 3''^ joint of the antennular peduncle is not shorter than the 2"'^; there are only 

 two teeth on the inner border of the proximal (outer) squame, the teeth of the distal squame 

 show a somewhat other form and the propodi of the 5"' legs are longer and slenderer. 



Scyll. arch/s {'L.) of the Mediterranean, however, bears the closest resemblance 

 to this new species. Two male specimens, respectively 54 mm. and 34 mm. long (outer antennae 

 included), from the Leyden .Museum are lying before me. The mediterranean species seems only 

 to differ by the carapace presenting three teeth instead of two, in the middle line before 

 the cervical groove. The two very small teeth, which in Scyll. bicuspid at us are placed abreast 

 between the posterior tooth and the cervical groove, are wanting in Scyll. arctus. Of the teeth 

 with which the inner margin of the proximal (outer) squame is armed, the second is the 

 largest and the difi"erence between these teeth is not so large as in Scyll. bicuspidatus. 

 Abdomen, sternum and thoracic legs show no differences at all. The differences, however, are 

 of little importance and it is therefore to be regretted that only one apparently young specimen 

 has been collected. 



Haswell records Scyll. arctus from Thursday I.sland, but Ortmann doubts of the correctness 

 of this observation, for he supposes that the author of the Catalogue of the Australian Crustacea 

 has not examined specimens from that locality and that Haswicll's description has been taken 

 from another source (A. E. Ortmann, in: Zoolog. jahrb. Abth. f Syst. VI, 1891, p. 42). 



6. Scyllarus Rlartcusii Pfeffer. (PI. Ill, Fig. 13, 131^). 



Scyllants lilartcnsii G. Pfefter, Die Panzerkrebse und die Clypeastfiden des Hamburger 

 Museums, mit einer Tafel. Hamburg iSSi, p. 48. 



