PART 1 GARTH : PACIFIC OXYRHYNCHA 329 



Atlantic analogue: Libinia rostrata var. bellicosa Oliveira (1944, p. 

 87), to which the Atlantic Panamanian and Brazilian specimens men- 

 tioned above should in all probability be referred. 



Diagnosis: Rostral horns strongly divergent. Spine at postlateral 

 angle directed outward, longest of any. Two teeth on basal antennal 

 article. Three lateral submarginal spines, a fourth commencing a flat- 

 tened ridge extending to posterior margin. Merus of male cheliped armed 

 with spines and tubercles ; manus with three teeth in gape. Male first 

 pleopod with tip grooved and sharply bent, a blunt keel on opposite side. 



Description: Carapace subglobose, regions elevated, well delimited 

 from one another, and covered with numerous spines, tubercles, and 

 tracts of curled setae. Rostrum horizontal, composed of two elongate 

 spines diverging widely toward extremities, width between tips equal to 

 one and one-half times basal width of rostrum. A strong preorbital spine 

 lying in a plane inclined to that of the rostrum, tip slightly recurving. 

 Orbit with a single closed fissure above, exorbital protuberance a cup into 

 which the small eye retracts completely. Principal spines and tubercles of 

 dorsal surface disposed as follows: a transverse row of three (not five) 

 tubercles on anterior gastric region, posterior to these a cluster of three 

 on mesogastric region, the median largest and crowded forward ; a low 

 tubercle on genital region ; a large boss on cardiac region ; an upstanding 

 spine on intestinal region above posterior margin ; a single inner hepatic 

 tubercle almost in line with anterior gastric tubercles ; an inner epibran- 

 chial tubercle similarly placed with respect to cardiac tubercles; two 

 diagonal lines of branchial spines, the inner row composed of two, the 

 outer of three spines, the spine at lateral angle of carapace the longest 

 and horizontally directed. Three strong pterygostomian spines, plus a 

 fourth subbranchial spine basally confluent with a thickened ridge extend- 

 ing continuously to posterior margin. 



Basal antennal article broad at base, slightly concave from side to 

 side, and bearing two blunt spines on outer margin. Ischium of outer 

 maxilliped with a longitudinal" groove; merus subcordiform, expanded 

 externally, notched internally to receive palpus, and inserting deeply and 

 narrowly into outer distal portion of ischium. 



Cheliped of male neotype less than twice the length of carapace with- 

 out rostrum ; merus stout, two prominent superior spines, the more proxi- 

 mal of which is directed outward, the more distal inward, an outer row 

 of three low tubercles, and a superior row of two in line with inwardly 

 directed spine ; carpus tuberculate ; manus granulate, superior and inferior 

 borders subparallel, fingers touching at tips, gaping widely at base, two 



