154 



as the merus and io-times as long as thick at its distal extremity; first segment 5-times as 

 long as thick at distal extremity, shorter than the sum of the following, the proportion being 

 as 1 : 1,22; the three following segments are equal and one and a half as long as thick; 

 chela one-eighth shorter than the first segment, fingers slightly longer than the palm. In the 

 specimen (a female?) from Stat. 162 the merus is 5,7-times as long as wide ; the carpus is 

 1,3-times as long as the merus and 10-times as long as thick at its distal extremity, carpal 

 segments and chela as in the male. 



The measurements of the third legs are indicated in the Table. Propodus in the male 

 (type) with 6, in the specimen from Stat. 162 with 7 rather short spinules, and a longer one, 

 half as long as the dactylus, at the distal extremity. The biunguicu late dactylus measures 

 one-third of the propodus and has a si en der form, being 6-times as long as broad at its 

 base ; the ventral, accessory hook is about half as long as the dorsal or principal one, its 

 anterior margin runs parallel with that of the other and it appears at its base just half as 

 broad as the dorsal hook ; both hooks are slender, the dorsal slightly arcuate, the other 



almost straight. 



Table. 



Relative dimensions of 



Merus 



Carpus 



Propodus 



Proportion between the length and the width of the merus . 

 Proportion between the length and the width of the propodus. 



N° 1 Stat. 162; N° 2 Stat. 258; N° 3 Stat. 273; N° 4 Stat. 315. 



Length of the male 8,5 mm., of the specimen from Stat. 162 8,75 mm.; the ova-bearing 

 female from Stat. 273 is hardly 7 mm. long. 



4- 



5,7 

 9 



f4. Athanas jedanensis de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI. 1910, p. 313. 



Stat. 273. December 23/26. Anchorage off Pulu Jedan, East coast of Aru-islands. (Pearl-banks). 

 13 m. Sand and shells. 1 male and 3 ova-bearing females. 



A new species of the Dimorphus group, characterized by the lack of the infra-corneal 

 spine and by the dactyli of the three posterior legs being biunguiculate, agreeing, as regards 

 the first character, with AtJi. areteformis Cout. and, as regards the second, with Ath. Granti 

 Cout. from the South Adelaide coast. 



Rostrum triangular, carinate, acuminate and projecting straight forward almost to or 

 just to the middle of the third antennular article, rarely, as in the largest female, to the apex 

 of the second; rostral carina sharp. Supra-corneal spine wanting. Extra-corneal spine acuminate, 

 reaching in the male by half its length beyond the eyes, in the female to the anterior margin 

 of the eyes or hardly beyond it ; infra-corneal spine wanting and represented, as in Atli. 

 areteformis, by a slight, broad, rounded prominence of the margin. 



