igiQ'] S. Kemp : Notes on Crustacea Decapoda. 387 



Macrophthalmus tclescopicus (Owen). 

 (Plate xxiv, figs. 10, 11.) 



1900. Afaci'oplitlialmiis verraiixi, Alcock, Journ. Asiat. Soc. Bengal, LXIX, 



P- 377- 

 1915. Mnci'opliflialmus telescoptcns, Tesch, Zool. Meded. Miis. Leuieti, I, 

 p. 161, pi. V, fig. 2. 



I accept Tesch's views on the synon^-my of this species as a 

 temporary measure, but further work is necessary before his con- 

 chisions can be accepted as final. The species, as understood by 

 Tesch, is one of extremeh^ wide distribution and it is quite pos- 

 sible that two or more allied forms may be confounded. Com- 

 parison of specimens from Australia, the Hawaiian Is. and the 

 Red Sea is a necessary step to further progress. 



The material at my disposal is very limited, but the three 

 males in which the chelipeds are extant differ considerably from 

 one another. 



In a male from Port Blair in the Andamans (one of those 

 examined by Alcock), with carapace 4*2 mm. in length and 67 

 mm. in breadth, the fine keel on the outer face of the palm (fig. 11) 

 near its lower border is decidedly sinuous and the fingers, as in 

 Miss Rathbun's figure ', gape very widely at the base. There is a 

 small molariform tooth at the proximal end of the dactylus and 

 another, in the form of a crest truncated anteriorly, near the tip 

 of the fixed finger. The teeth on the lateral margin of the cara- 

 pace behind the orbital tooth are blunt. 



In a larger male, also from Port Blair, with carapace 15 mm. 

 in breadth and 9 mm. in length, the chela is of the same type, 

 but the keel on the outer face of the palm is a little straighter. 

 The lateral teeth of the carapace, behind the orbital angle, are 

 sharp and the meral segments of the first walking legs (which have 

 been lost in the smaller specimen) bear a dense patch of fur on the 

 underside. 



A male from the northern end of the Gulf of Manaar, with 

 carapace "j'^ mm. in length and I2'4 mm. in breadth, has sharp 

 lateral teeth on the carapace and no furry patch on the lower side 

 of the merus of the first walking legs. The keel on the outer face 

 of the palm is much less sinuous in this specimen (fig. 10), the 

 fingers do not gape, the tooth on the fixed finger is longer and a 

 little more remote from the apex, while the molariform tooth on 

 the dactylus is longer and broader and situated more nearly in the 

 middle of the finger length. In this individual the terminal seg- 

 ment of the abdomen is proportionately broader than in those from 

 Port Blair. 



From the material at my disposal I am not able to decide 

 whether the differences in these males are specific or merely a 

 matter of variation. 



1 K. Danske Vidensk, Selsk. Skrift. (7), naturvid. og math., V, p. 322, text- 

 fig. 6(1910). 



