48 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53. 



steamer Albatross at Laredo Bay, in the Straits of Magellan, Janu- 

 ary 22, 1888. These have received Cat. No. 47784, U.S.N.M, and 

 become paratj^pes of the new species; from them a single female 

 was selected to serve as the species type with Cat. No. 47785, U.S.N.M. 



/Specific characters of female. — Cephalothorax elliptical, a little 

 less than twice as long as wide and flattened dorso-ventrally, with 

 a well-defined lateral lobe on either side at the posterior end; ros- 

 trum short and wide and broadly rounded; tripartite eye large and 

 so deeply buried as to be nearer the ventral than the dorsal surface. 

 Neck comparatively wide and bent ventrally at an angle of 45° ; 

 third thorax segment elongated, but not much widened posteriorly; 

 fourth segment relatively long and nearly as wide as the trunk, 

 from which it is separated by a deep groove. 



Trunk narrow-cylindrical and seven times as long as wide, squarely 

 truncated posteriorly; abdomen hemispherical and half the diame- 

 ter of the trunk, with well-defined anal laminae, each armed with 

 three long plumose setae and two smaller, non-plumose ones; ^gg 

 strings one-third the diameter of the trunk and two-thirds longer 

 than the entire body, with narrow masses of cement substance at 

 their tips. 



First antennae slender and three- jointed, basal joint the shortest, 

 the other two about equal and well armed with setae; second antennae 

 with a stout basal joint and a short and strongly curved terminal 

 claw; proboscis short and wide, mouth opening large, circular, and 

 terminal, surrounded by a narrow stiff rim; first maxillae minute, 

 one-jointed, tipped with two tiny setae and fastened to the lateral 

 wall of the proboscis; second maxillae comparatively large, basal 

 joint long and stout and armed with a short spine on the posterior 

 margin near the center, second joint half as long and tipped with a 

 short curved claw; the distal end of the basal joint and the proximal 

 end of the second joint are tapered so that the appendage is narrowed 

 at the joint. The basal laminae of the first three pairs of swimming 

 legs are rounded triangular, with a narrow sinus on the inner mar- 

 gin near the base, each one split diagonally from the apex of the 

 triangle to the base of this sinus. The fourth pair has a knob in 

 place of the sinus and the split extends only to the center of the 

 lamina. 



Total length, G.25 mm. Length of trunk, 5.12 mm. ; width, 0.75 mm. 

 Length of egg strings, 10.50 mm.; width, 0.25 mm. 



Color (preserved material), a uniform light yellow, the carapace 

 and swimming legs with spots of dark brown pigment more or less 

 sj'mmetrically arranged. 



(fissipcs, fissus, cleft and pes, foot, alluding to the diagonal split in 

 the basal laminae of the swimming legs.) 



Type.— Female, Cat. No. 47785, U.S.N.M. 



