1912.] S. Kemp & R. B. S. Seweli. : Notes on Decapoda, III. 27 



Brachynr(t. 



Tribe Dromiacea. 



Family HOMOLIDAE. 



Homola megalops, Alcock. 



Homola niegalops, Alcock, 1899, p. 9 ; 1901, p. 62, and ///. Zool. 

 Invest., Crust., pi. xiv, figs, i, la. 



Nineteen males and ten females (live ovigerous), ranging in 

 length of carapace from I2"5 to 54 mm., were obtained at St. 391. 



Many of these specimens are of considerably greater size 

 than those which afforded Alcock material for his original des- 

 cription and we notice that large males differ from his account 

 in the following features : — 



The chelipeds are both longer and stouter ; the merus and 

 carpus are distinctly broader than the meri of the ambulatory 

 legs and the chela may reach to the end of the propodus of the 

 next limb. 



The whole under surface of the chela, except for the extreme 

 tips of the fingers, is clad in a thick and deep, dark brown 

 velvety pubescence which is not present in females. 



The palm is very conspicuousl}^ longer than the dactylus 

 and at the base of the latter, on the inner edge, there is a stout 

 tooth which is not found in females or young males. 



The spines on the anterior region of the carapace, though 

 alwa3's distinct, are less prominent in large individuals. 



Measurements of the carapace (including rostrum) and cheU- 

 peds of forty-two examples of this species, show that whereas 

 in the female the growth of the cheliped is proportional 

 to that of the carapace throughout the whole period of its 

 existence, this, as in many other species of Brachyura, is by no 

 means the case with the male. In young examples of the latter 

 sex, in which the carapace does not exceed 30 mm. in length, the 

 cheliped has the same proportions as in females ; but, as growth 

 continues, there is a relatively greater increase in the length of 

 the chelate leg. In females and young males the proportion of 

 cheliped-length to carapace-length is approximately i"5, whereas 

 in large males it may reach as much as 2"0. 



This marked difference between the sexes is illustrated in the 

 accompanying figure (p. 28). 



Tribe Oxystomata. 



Family DORIPPIDAE. 

 Ethusa andamanica, Alcock. 



Etnusa andamanica, Alcock, 1899, p. ^^^ and III. Zool. Invest. 



Crust., pi. xiv, fig. 8. 



It is with some doubt that a single ovigerous female from St. 

 391 is referred to this species. 



