MACRUROUS DEOAPODA OF THE SUDANESE RED SEA. 365 



to rank as a species distinct from G. spinosus. Even after ten years pre- 

 servation m spirit the dark spots on the sixth, seventh, and eighth thoracic 

 segments, and on the first, fourth, and fifth abdominal segments are distinctly- 

 visible, very distinct on the sixth thoracic and first abdominal segments, 

 paler on the seventh thoracic segment, and very faint on the other segments. 

 Distribution. Not actually recorded from the Red Sea previously though 

 noted from Aden by Nobili ; for other records, see Kemp, 1913. 



DECAPODA. 



Suborder NATANTIA. 



Tribe PEN.EIDES. 



Family PEN-EIDiE. 



Subfamily Pen^in^e, Alcoak. 



Genus Pen^eopsis, A. Milne- Edwards. 



PENiEOPSIS stebbingi {NoUli, 1904). (PI. 27. figs 7-10; PI. 28. fig. 13.) 



Metapeneeus stebbingi, Nobili, 1904, p. 229. 



„ 1906 a, p. 15, pi. 1.%. 2. 



„ „ Alcock, 1906, p. 50. 



„ ,, De Man, 1911 a, pp. 9 & 54. 



Localities. Station I. E, 14 ? and 15 <$ , 70-90 mm. Station VIII. A, 

 2 c?, 50 mm. and 55 mm. Station X., 1 $ , GO mm. Station I. B, 1 juv., 

 27 mm. From Ray's stomach, several juv. 



Remarks. Nobili makes no mention of the fact that this species is without 

 exopodites on the last pair of thoracic legs. It, therefore, clearly belongs to 

 the monoceros group of species characterized by the absence of exopodites on 

 the last pair of thoracic legs, and by the fact that the merus of the last pair 

 of thoracic legs in the male is notched at its proximal end. It differs from 

 most of the members of this group by having 6-8 small movable spinules on 

 the telson. 



I have very little to add to Nobili's description, but his figures are perhaps 

 a little too diagrammatic. I have refigured the carapace, thelycum, and 

 petasma, and added a figure of the notch on the merus of the last thoracic 

 legs of the male. There is a distinct trace of an extra-orbital spine, and the 

 lower anterior corner of the carapace is rounded and not acute as in Nobili's 

 figure. 



P. stebbingi is a very distinctive species as far as the thelycum and petasma 

 are concerned, and adult specimens are readily recognizable on these 

 characters. 



