Rathbun. — SOUTH AMERICAN CRUSTACEA 
45 
SOUTH AMERICAN CRUSTACEA 
Mary J. l^atí)büo 
(Department of Marine Invertebrates, U. S. Nat. Museum) 
¿' ^ : :. ^ 
Among a lot of Crustacea sent by Prof. C. E. Porter to the 
United States National Museum, there are an undescribed crab 
and shrimp, besides several rare species which are worthy of 
note. 
Tricliodiictylus (Dilocarcimis) spinifer (Mihie Edwards). 
DiLocARciNus SPINIFER Milue Edumvcls, Ann. Sci. Nat. (3) 
Zool., XX, 115 [181], 1853; Arch. Mus. Hist. Nat. Paris, 
VII, 178, pi. XIV, figs. 3-3^ 1854. 
M^atto-Grosso, Brazil; M. Dabbene; one small male. 
In this specimen, the lobe or spine usually found in old 
specimens on the outer slope of the orbital spine is absent, and 
is represented only by a slight convexity. The suborbital 
spines imniber five on one side and six on the other. The 
third to sixth abdominal segments are more or less fused; 
between the third and fourth a narrow suture is quite plainl}^ 
shown in the middle third, while there are faint indications of 
the next two sutures in the middle. 
Pinnixa valdiviensis, sj). nov. ( Lámina III, figs. 2 and 3.) 
Male. — Carapace nearly twice as wide as long, regions fain- 
tly indicated, surface covered with very fine reticulating lines 
and scattered punctae; cardiac region marked by a short blunt 
transverse ridge either side of the middle; hepatic region 
