8o 



colour, that occupies one-third the width of the tergum. The thoracic legs, except those of 

 the i st pair, are marked with four slate-colourecl rings, which are also mentioned by Stimpson. 

 The young male from Stat. 273 is 19 mm. long, the outer antennae included; it is of 

 a much paler colour, but the characteristic oval fieck on the i st abdominal tergum is present. 

 The posterior tooth on the outer margin of the proximal (outer) antennal squame is somewhat 

 more distinct than in the three other individuals. 



Ortmann (1. c.) regards this species as identical with Scyll. vitiensis (Dana) and in my 

 first description (1. c, p. 501) I myself was also inclined to the supposition that both species 

 once should prove to be identical. This opinion now appears to me to be erroneous. Scyll. 

 vitiensis (Dana) differs, indeed, by the following characters. The carapace carries two teeth, 

 instead of three, the tooth immediately behind the cervical suture wanting completely. Dana 

 says "the gastric spine has three or four squamiform tubercles, posterior to it; and then follows 

 a smooth surface"; this is not the case in Scyll. sordidus (Stimps.), the cardiac region terminating 

 in this species, anteriorly, in a strong acute tooth. The tergum of the i st abdominal somite 

 and the anterior half of the 2 nd and 3 rd terga are "but faintly divided into a few areolets", 

 whereas in Scyll. sordidus the squamiform prominences are here as distinctly developed as on the 

 posterior half. The two following somites have also a different appearance. The inner margin 

 of the 4 th joint of the external antennae is distinctly armed with 3 well developed teeth. The 

 penultimate joint of the antennular peduncle is but little longer than, and not nearly twice as 

 long, as the last. The carpus and the propodus of the 2 nd legs have a slenderer form; in 

 Dana's species the propodus is 7-times as long as thick at its base, in Scyll. sordidus 4-times. 

 The notch at the end of the sternum is obtuse at its extremity, but acute in Scyll. sordidus 

 (confer J. G. de Man, 1. c. fig. 58). The oval dark fieck on the i st abdominal somite, finally, is 

 wanting in Scyll. vitiensis. 



General distribution: Hongkong (Stimpson) ; Java Sea (de Man) ; Singapore (Nobili). 



5. Scyllarus bicuspidatus (de Man). (PI. II, Fig. 12 — I2r). 



Arctus bicuspidatus J. G. de Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. IX, 1905, p. 589. 



Stat. 310. February 12, 1900. 8° 30' S., U9°7'.5E. Ji m. Bottom: sand with few pieces of 

 dead coral. 1 young female. 



A new species, most closely resem bling Scyll. arctus (L.) and also related to 

 Scyll. RIartensii Pfeffer, with which it will be compared in the following lines. The few differences 

 from Scyll. arctus will be mentioned at last. 



The whole leng-th from the anterior margin of the outer antennae to the end of the 

 telson is 25 1 /, mm.; the carapace, measured in the middle line, is 7 1 /.;, mm. long, the distance 

 between its anterodateral angles 8y 3 mm., the abdomen 13 mm. The anterior margin of the 

 carapace is armed in the middle line with an acute tooth, directed forward and an other 

 somewhat larger acute tooth occurs on the middle of the gastric region, both teeth 

 being directed obliquely upward ; midway between the extremity of the gastric tooth and the 



