589 



lateral carinae distinctly carinate. Frontal process twice as broad 

 as long. Squamiform sculpture on the abdominal terga and pleura 

 as in A. sordidus, but more couspicuous; fourth tergum much 

 more prominent in the middle line tban the rest. 



Proximal (outer) squame of outer antennae as long as broad, 

 outer border with three or four flattened teeth, inner with five 

 or six. Lobes of the distal squame rounded, one more in nuraber 

 than in A. sordidus. Notch of first joint of sternum semicircular, 

 fifth joint with median tubercle. 



Thoracic legs with dark, slate-coloured rings as in A. sordidus, 

 but no dark fleck on the first abdominal tergum. 



Two young males, the larger 21 m.m. long, the outer antennae 

 included. 



This species is probably identical with Scyllarus sordidus Nob. 

 from the Persian Gulf (Nobili, in: Buil. Muséum Paris, 1905, 

 p. 160), and in this case Nobili's species may henceforth bear 

 the name of gibherosus, because an Arctus sordidus has already 

 been described by Stimpson ; when they are different, then I pro- 

 pose for the Persian species the name of Nohilii, at least when 

 it really belongs to the genus Arctus. 



4. Arctus bicuspidatus n. sp. 



Station 310. Lat. 8° 30' S., long. 119° 7',5 E. Depth 73 M. 



Closely related to Arctus Martensii PfefFer. 



Carapace carrying two acute, sligbtly upturned teeth in the 

 middle line, namely one on the anterior margin and a soniewhat 

 larger on the middle of the gastric region ; no tooth immediately 

 behind the cervical groove. Squamiform prominences on the gastric 

 and cardiac regions indistinct. Orbits as in A. Martensii, situated 

 just as near to the lateral margins. Branchial regions devoid 

 of squamiform prominences between those of the hardly prominent, 

 lateral carinae and those of the lateral margins. Frontal process 

 less broad, only twice as broad as long. Areolated posterior part 

 of the Ist abdominal tergum as long in the middle as laterally, 

 the furrows between the areolae parallel with one another and with 



