CRUSTACEA OF THE MERGUI AECHIPELA.GO. 193 



millim. millim. 

 Length of the dactylopodites of the last pair 



of legs 7 6f 



Length of the hands 21 I83- 



Length of the penultimate j oint of the male 



abdomen 4^ 



104t. Sesarma Keaussi, n. sp. (PL XIY. figs. 1-3.) 

 Sesarma longipes. White, List of the Specimens of Crustacea in the 

 Collection of the British Museum, London, 1847, p. 39 {nee Krauss). 



A single male specimen was found at the island of Kisseraing. 

 This species is most closely allied to Sesarma longipes, Krauss, 

 from the seas of Natal, and represents it in the Bay of Bengal, 

 the two differing from each other only in subordinate characters. 

 It will therefore be suflBcient if I refer to Krauss's description 

 and figure of Sesarma longipes (Die Siidafrikanischen Crus- 

 taceen, Stuttgart, 1843, j). 44, Taf. iii. fig. 2), and point out the 

 distinctive characters of the new form. 



The anterior margin of the front, which is nearly straight in 

 ^S*. longipes, presents a rather deep median sinus in the Indian 

 species. In S. longipes a single tooth is found behind the ex- 

 ternal orbital angle, but in S. Kraussi two teeth are observed 

 behind the extraorbital tooth, the posterior one being very 

 small. The penultimate joint of the male abdomen in ^. Kraussi 

 is a little longer in proportion to the breadth than in S. lon- 

 gipes. The hands of the male are of somewhat different size, 

 the left being the larger. The outer surface of the palm is almost 

 perfectly smooth, but a few minutely granulated lines occur 

 close to the articulation with the wrist ; two or three similar 

 lines may also be observed on the upper margin of the palm, 

 but the convex inner surface is nearly smooth, only three or 

 four small tubercles being present near the middle. The fingers 

 have pointed tips ; the upper margin and the outer surface of 

 the mobile finger are perfectly smooth, but the outer surface of 

 the index is armed with a longitudinal row of 8-10 small, acute 

 tubercles, with some minute hairs between them, the row pro- 

 ceeding from the base of the finger to near its horny tip. This 

 row of acute tubercles occurs along the middle of the external 

 surface of the index, whilst in ;S^. longipes it occurs on the 

 under margin o£ the finger. Each finger is armed along its inner 



LINN. JOURN. ZOOLOGY, VOL. XXII. 13 



