120 A. E. Verrill — Species of Grapsoid Crustacean. 



Its range extends from Florida through the West Indies to 

 Trinidad. 



The new form seems to be a subspecies or a variety of S. 

 Ricordi, which may be actually in process of development into 

 a genuine species, by natural selection and physiological isola- 

 tion. 



It was found living under stones in dry upland fields and 

 nearly barren waste lands with thin soil, where the scanty 

 vegetation consisted of wiry grasses and dwarfed shrubs and 

 weeds. It was associated with a few species of ants, beetles, 

 cockroaches, spiders, land-shells, etc. When the stones were 

 turned over it usually ran away very actively and sought 

 shelter under other stones, but did not seek the water, as most 

 species do. Its general appearance was very unlike S. Ricordi. 

 It usually had a sordid dirty color, due largely to adherent 

 particles of soil. It may be described as follows : 



Sesarma Ricordi, var. terrestris, subspecies or var. now 



The carapace appears more rough and uneven than in the 

 ordinary form, for it is more strongly areolated and the 

 branchial areas are more swollen, so that the vertical thickness 

 is greater and the reticulated areas of the sides are broader, 

 giving a larger surface for aeration of the water, and indicat- 

 ing' larger gill cavities and gills. The dorsal surface of the 

 carapace is covered with more numerous and larger granules, 

 bearing numerous short dark hairs, very evident under a lens 

 of low power, and capable of holding adherent dirt ; the plicae 

 on the postero-lateral sides are stronger and more granulous ; 

 the lateral marginal edges are more sinuous anteriorly, owing 

 to the more swollen branchial chambers. The anterior frontal 

 margin is less sinuous, the median indentation often being 

 obsolete or faint. 



The ambulatory legs are distinctly larger and longer than in 

 the common form. When the legs are folded the tooth on the 

 distal angle of the merus joint of the legs of the third and 

 fourth pairs reaches considerably (2-3 mm ) beyond the outer orbi- 

 tal angle, while in Ricordi it just reaches it, or only slightly 

 exceeds it (-5 mm or less). The proportion of the merus joints 

 of these legs to the breadth of the carapace is 1 : 1*36. In 

 Ricordi, 1 : 1*5. Ratio of same to length of carapace, 1 : 1*2. 

 In Ricordi, 1 : 1*4. 



The colors, when living, appear dull or sordid yellowish 

 brown, or mud-color, due partly to adherent dirt, often specked 

 or mottled with red or reddish brown. Fresh specimens 

 cleaned in alcohol were variegated with pale bluish gray, dark 

 brownish .gray, and blackish, with some red and yellowish 



