230 



Memoirs of the Indian Museum. [Vol. V, 



continued on the mobile finger. The other is parallel to it and runs close to the 

 inferior margin, extending to the tip of the immobile finger. Neither the upper nor 

 the lower edges of the palm are granulate. In the middle of the fixed finger, on the 

 inner edge, is a large serrated crest, like a cock's comb, with the distal serrations 

 much larger than the proximal. At the base of the dactylus is a strong molariform 

 tooth. The chela of the female (text-fig. lOc) is much more slender, about four times 

 as long as wide, and the fingers are unarmed. It bears rows of setae, similar to 

 those of the male and the surface is covered with a fine pubescence. 



The third walking legs are the longest, fully twice the length of the carapace. 

 In all four pairs the upper and lower borders of the meri are granular and on these 

 segments in the first three pairs of the female and the two middle pairs of the male 

 there is on the anterior margin a small sub-terminal spine. The dactyli are flattened 

 and all the segments bear long hairs. 



In the male the thoracic sterna bear numerous granules, which also occur, 

 though less abundantly, on the abdomen. In this sex the sutures between the 3rd 

 and 4th and between the 4th and 5th abdominal segments are very fine, the joints 

 being almost immovable, and on either side of these sutures and of that between the 

 5th and 6th segments there is a large pit or depression (text-fig. lOrt'). The last seg- 

 ment of the abdomen of the female is about one and half times as broad as long. 



Only two specimens of this species were obtained ; they yield the following 

 measurements (in mm.): — 



c? 9 



Length of carapace . . . . . . . . I4'8 lyz 



Breadth across outer orbital angles . . . . 14-9 17-6 



Greatest breadth . . . . . • . . 17-6 208 



Breadth of front . . . . • . . 2-6 27 



Macrofhthahnits gastrodes is apparently allied to M.serratus, White', from the 

 Philippine Is. and Hongkong, and to M. definitiis, White \ which is known from the 

 first of these localities and from Australia. It is easily distinguished from both these 

 forms by many of the characters enumerated above. 



In life the species is entirely covered with fine mud ; when this was removed the 

 specimens were found to be of an almost uniform clay colour with a purplish-pink 

 flush on the carapace. The scarcity of the species in our collection is perhaps due to 

 the fact that it burrows; in both individuals, however, the cornea is jet-black. 



Both specimens were found in the outer channel of the Chilka Lake, on the 

 muddy ground between Satpara and Barhampur I. The male was obtained in 

 March in water as salt as that of the Bay of Bengal in the vicinity of the lake-mouth 

 (sp. gr. 1-0265), while the female was found in September in water that was quite fresh. 



The two specimens, types of the species, bear the numbers 9157-8/10 in the 

 Indian Museum Register. 



' Adams and White, Crust. Voy. ' Smnarnng \ p. 51 (1848) and Stimpson, S»(.///jso«. Mwc. Co//. 

 XlylX, p. 96, pi xiii, fig. 3 (1907). 



^ Adams and White, ibid., p. 51 (1848) and Ortmann, Zool. JaJirb., Syst., X, p. 342 (1897). 



