220 WALTER GARSTANG. 



The same remarks apply to my specimens of C. hepatica 

 from Honolulu and the Sulu Sea. On the other hand, Alcock 

 states that the pterygostomial region of several species (C. 

 exanthematosa, gallus, pustulosa, and Woodmasoni) 

 is characterised by possessing but '' few scanty hairs/^ When 

 the study of habits is considered worthy of the attention of 

 men of science, we shall perhaps learn whether or not it is 

 true, as I venture to believe, that the species with few ptery- 

 gostomial hairs live in cleaner ground than those having the 

 outer part of the pterygostomial regions '^ densely hairy/' 

 That Calappse do inhabit mud, as well as sand, is certain 

 from Macgillivray's remark (1852, vol. i, p. 102) that on a 

 coral reef off the coast of Queensland containing all varieties 

 of coral, mud and sand, '' smooth Calappae seek refuge .... 

 in the shallow muddy pools .... by burrowing beneath the 

 surface." 



2. Matuta picta,^ Miers. 



The figure (Plate 13, fig. 2) which I give of this species 

 has been carefully drawn by Mr. Bayzand from a specimen 

 (an adult male) brought back by Mr. G. C. Bourne from Diego 

 Garcia in 1892. It represents the crab lying in a somewhat 

 inclined position, the anterior part of the body being elevated 

 so as to display more effectually the infra-orbital and ptery- 

 gostomial regions of the carapace. 



The genus Matuta is closely related to Calappa, but in 

 the form of the carapace and chelipeds is less specialised than 

 the latter type. In the broad swimming plates of the hind- 

 most pair of thoracic legs, in the obsolescent teeth on the 

 antero-lateral margins of the carapace, and in the great pair of 

 epibranchial spines, Matuta betrays obvious signs of deriva- 

 tion from an early progenitor of the Portunid type, such as 



1 My specimeu is identical with M. pi eta of Miers (1877) and the 

 synonymous M. lunaris of Leach (1817). It would be referable to the 

 more comprehensive M. Banks ii of Alcock's recent revision (1896), were it 

 not for the fact that the " posterior granulated ridge " is prolonged as far as 

 the epibranchial spine, on the posterior border of which it dies away. Alcock's 

 distinctions under this head are far from satisfactory. 



