CRUSTACEA OF THE MERaUI ARCHIPELAGO. 181 



Section" D. — Sesarmce tTie cephalothorax of which is armed 

 with one or two epibranchial teeth behind the extraorbital 

 tooth, and in which the palm of the anterior legs of the 

 male is not araied with two oblique, parallel, minutely pecti- 

 nated ridges. 



This Section is represented in the Indo-Pacific Eegion by a 

 rather large number of species, some of which it is diflScult to 

 distinguish. 



99. Sesarma TJiiNiOLATA, White. 



Sesarma tfeniolata, White, List Crust. Brit. Mus. p, 38 (1847) ; Miers, 

 Crustaceans from Duke-of-Tork Island, Proc. Zool. Soc. 1877, p- 137 

 (footnote). 



Sesarma tEeniolata, de Man, Notes from the Ley den Museum, vol. ii. 

 p. 26. 



Sesarma Mederi, Milne-Edwards, Ann. Sci. Nat. t. xx. p. 185 (1853). 



Three fine male specimens were collected. In all these 

 examples the upper surface of the cephalothorax is densely 

 covered with small tufts of hairs. 



Sesarma tceniolafa, White, is closely allied to Sesarma Lqfondi, 

 Hombr. & Jacq.,the cephalothorax and the ambulatory legs in both 

 species being similar. The former, however, may be distin- 

 guished at first sight by the longitudinal pectinated ridge on the 

 upper margin of the palm of its chelipedes, and by the occur- 

 rence of a longitudinal transversely striated ridge on its mobile 

 finger. These two species diff'er from many other species of 

 this section, in which the distance between the extraorbital 

 teeth is greater than the length of the cephalothorax (as, e.ff., 

 from S. tetragona, S. rotundifrons, S. intermedia, S. sinensis), by 

 the upper margin of the arms of their anterior legs terminating 

 in a strong acute tooth at its distal end, and by the anterior 

 margin being armed with a prominent denticulated tooth. 

 S. tceniolata serves to connect this section of the genus with the 

 preceding, as the upper margin of the palm of the anterior legs 

 is furnished with only a single pectinated ridge. 



A careful examination of a typical specimen of S. Mederi in 

 the Museum of Paris convinced me that this species is identical 

 with S. tceniolata, White. Although the latter name has priority, 

 the first description of this species was published by Milne- 

 Edwards. 



