1912.] S. Kemp & R. B.S. SEWELL: Notes on Decapoda, III. 27 
Brachyura. 
Tribe Dromiacea. 
Family HOMOLIDAE. 
Homola megalops, Alcock. 
Homola megalops, Alcock, 1899, p. 9; Igo1, p. 62, and Ill. Zool. 
Invest., Crust., pl. xiv, figs. 1, Ia. 
Nineteen males and ten females (five ovigerous), ranging in 
length of carapace from 12°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 Jarge 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 conspicuously 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 
always distinct, are less prominent in large individuals. 
Measurements of the carapace (including rostrum) and cheli- 
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 1°5, whereas 
in large males it may reach as much as 270. 
This marked difference between the sexes is illustrated in the 
accompanying figure (p. 28). 
Tribe Oxystomata. 
Family DORIPPIDAE. 
Ethusa andamanica, Alcock. 
Ethusa andamanica, Alcock, 1899, p. 33, and IU. Zool. Invest. 
Crust. pl. xiv, fig. 8. 
It is with some doubt that a single ovigerous female from St- 
391 is referred to this species. 
