7* 



clescribed by Dr. Nobili, in: Buil. Mus. Paris, 1905, p. 160, under the name of Scyll. sordidus 

 (Stimpson), — when it should prove to be indeed different from Scyll. gibberosus. When I now, 

 however, compare the type of gibberosus with Nobili's more detailed description of Scyll. Nobilii, 

 in: Buil. Scientif. France et Belgique, XL, 1906, p. 56, PI. IV, fig. 15 and PI. VI, fig. 27, I find 

 only these differences, i° that the anterior segment of the sternum appears in gibberostis more 

 deeply emarginate with the antero-lateral angles obtusely-pointed, a difference perhaps owing 

 to the young age of this specimen, which is only 21 mm. long, while the specimens, described 

 by Nobili under the name of Scyll. sordidus, were almost twice as long, viz. 36 and 37 mm., 

 2" because the "petite pièce élargie en marteau" described by Nobili as situated in front of 

 the anterior tooth of the carapace, presents a somewhat other form. 



When the two species afterwards once might prove to be identical, then the name of 

 gibberosus has, of course, the priority. — 



Scyll. Paulsoni Nob. is not included in this key, because in Nobili's description (Faune 

 Carcinologique de la Mer Rouge, 1906, p. 87) nothing is said about the thoracic legs and too 

 little about the abdomen. Scyll. delfini (Bouv.), which apparently belongs to the American 

 Fauna, is also omitted. 



1. Scyllarus viticnsis (Dana). (PI. II, Fig. 9, ga). 



Arctus vitiensis J. D. Dana, U.S. Exploring Exped. Crustacea, 1852, p. 517, PI. 32, fig. 7. 

 Arctus viticnsis J. G. de Man, in: Archiv f. Naturges. 53. Jahrg. 1888, p. 485. 



Stat. 115. July 9/1 1. East side of Pajunga Island, Kwandang Bay. Reef. 1 young specimen. 



This specimen is 16 1 /., mm. long from the anterior extremity of the outer antennae to 

 the end of the telson, but this species attains a length of 25 mm. The distance between the 

 antero-external angles of the carapace measures 5,5 mm.; when the antennular somite is included 

 and when measured in the middle line, the carapace appears to be 5,2 mm. long. The upper 

 surface of carapace and outer antennae is covered with short, minute plumes. The median 

 tooth on the anterior border of the carapace is small and sharp, but that of the gastric 

 region is much larger, directed obliquely upward, rat her sharp in a lateral 

 view, obtuse when seen from above; the squamiform prominences posterior to it, are 

 barely distinguishable, not at all prominent, but a small tubercle on either side of the gastric 

 tooth is distinct. For the rest the gastric region appears quite smooth and shining, there where 

 the plumes are wanting. A much lower placed couple of small, little prominent and obtuse 

 teeth occur immediately behind the cervical groove in the middle line, and on each side of it 

 one observes an obtuse tooth ; the squamiform prominences of the cardiac region are, however, 

 barely discernible, those of the intestinal region are more distinct. The lateral carinae are much 

 prominent on the inner side of the orbits and cut into two subacute teeth; that part of the 

 lateral carinae which is situated posterior to the cervical groove, is little prominent, rounded, 

 covered with low, squamiform prominences and ends anteriorly in a subacute tooth. The orbits 

 are circular. The posterior margin of the carapace is slightly concave in the middle. 



