58 



U.S. NATIONAL MUSEUM BULLETIN 292 



Atya occidentalis Newport, 1847, p. 159 [type-locality: Jamaica]. — Pocock, 1889, 

 p. 11, pi. 2: figs. 3, 3a.— Bouvicr, 1925, p. 312, figs. 700-702. 



Atya robusta A. Milne-Edwards, 1864, p. 148, pi. 3: fig. 1 [type-locality: "New 

 Caledonia" (see Holthuis, 1966, p. 237)]. 



Atya innocous. — Holthuis, 1966, p. 237. 



Atyia occidentalis. — V61ez, 1967, p. 42. 



Diagnosis. — Orbital margin unarmed. Kostrum witliout dorsal 

 teeth, lateral lobes obtuse, ventral margin virtually unarmed. Ventral 

 margin of pleuron of second abdominal somite unarmed, those of 

 third through Jijth somites usually bearing row of small, sharp denticles. 

 Eyes not reduced. Basal segment of antennular peduncle \vithout 

 dorsal spines proximal to series bordering distal margin. Pereiopods 

 witliout exopods. Fingers of chelae of first and second pereiopods 



Figure 8. — Jtya innocous, male (carapace length 25.8 mm) from Dominica station 46. 



bearing terminal tufts of long hair. Carpus of second pereiopod 

 broader than long. Last three pereiopods bearing depressed horny 

 scales. IVlerus of third pereiopod noticeably broader than that of 

 fourth pereiopod, usually between 0.2 and 0.3 as broad as long. Ap- 

 pendix masculina on second pleopod of male broad lobe bordered 

 with slender curved spines. Body without distinct dark-colored trans- 

 verse bands near anterior and posterior ends of abdomen. A moderately 

 large species, maximum postorbital carapace length at least 34 mm. 



Color in life. — Two phases, green and brown. 



Brown Phase: Ground color of cephalothorax dark brown (brown- 

 ish black chromatophores forming reticulate pattern over tan). 

 Dorsum of carapace with dark brown longitudinal stripe extending 

 from base of rostrum to posterior margin, becoming broader pos- 

 teriorly. Stripe continuing onto abdomen but broken by very narrow 



