146 Bulletin, Vanderhilt Marine Museum, Vol. II 



Island, Conway Bay, Galapagos Islands, March 11, 1926, collected by 

 the "Ara," William K. Vanderhilt, commanding. 



Color : Deep purplish beneath the black setae. 



Technical description : Carapace oval, four-fifths as wide as long, 

 interorbital border nearly four-fifths of total width of carapace. Cara- 

 pace broader through the anterior two-thirds, decidedly narrower 

 posteriorly ; rather flattish, with the frontal border somewhat deflexed ; 

 aerolations only faintly indicated. Carapace covered with low squam- 

 ous tubercles, which are larger and more abundant toward the anterior 

 region. Each tubercle is fringed anteriorly with short, stiff setae, and 

 the posterior part of the carapace also has bristly setae between the 

 tubercles ; the frontal border is bilobed in the median region, a deep 

 sulcus running back from this median sinus onto the gastric region; 

 the frontal margin is irregularly set with uneven, denticle-like tu- 

 bercles. Just below these the pterygostomian region is also tubercu- 

 late. There are six teeth (including the postorbital tooth) on the 

 anterolateral margin, the first four are large and are bi- or triden- 

 tate, the posterior two are smaller and acute. The superior orbital 

 margin is set with denticles; the inferior orbital margin is also den- 

 ticulate and has a deep hiatus near the external angle. The male 

 abdominal belt is narrow, seven-segmented, with the distal segment 

 triangulate. The female belt is also seven-segmented, oval, narrow, 

 proximally, wider throughout the distal half. The eyestalk is bulbous 

 basally, constricted abruptly below the cornea and thence tapering. 

 The cornea is small and set obliquely at the end. The inner antennae 

 are small and fold transversely within the septum. 



The external maxillipeds are squarish and close the buccal cavern 

 tightly except the aperture of the efferent channel, and a very narrow 

 space between the ischia, which latter is covered by a sieve-like setae. 

 The exognath is elongate and bears a tooth-like projection on its inner 

 distal margin and a slender palp which arises from its distal end; 

 the ischium is subrectangular and is traversed on its outer surface by 

 a longitudinal depression and is denticulate on its inner margin; the 

 merus is about one-half as long as the ischium, is trapezoidal, with a 

 slight emargination below the efferent aperture; the palp arises just 

 inside this emargination and the inner distal angle of the merus is 

 angulated beneath the palp. The palp is rather fleshy, three-jointed. 



The chelipeds are conspicuously unequal in both sexes, but this in- 

 equality is more pronounced in the male. The three basal joints are 



