638 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii. 



Thoracic area considerably smaller than the cephalic and somewhat 

 angular; digestive glands prominent, shaped like a comma, with the 

 convex sides toward each other. 



Free segment short and narrow, about one-fourth the width of the 

 carapace, the bases of th(^ fourth legs projecting strongly on either 

 side. Genital segment ovate, considerably more tiian half as wide as 

 the carapace, and three-tifths as long, with smoothly rounded cornei's 

 and a slightly emarginate posterior border. Abdomen very small, 

 wider than long, with small, widelv separated papilla. Egg tubes 

 about the same diameter as the abdomen and short, onl}' a trifle longer 

 than the genital segment, each containing but twenty eggs. 



Of the appendages the anterior antenna^ are stout, the two joints 

 about the same length; the posterior antenn;e have a large basal joint 

 supplemented by a short and stout accessory spine, while the terminal 

 joint is long and abruptly bent. 



The tirst maxilhe are very large for a female, strongly curved and 

 blunt at the tip. The second maxillpe are also very large, cut about 

 to the center, the branches thick and stout, and flanged along either 

 side. These branches are widel}^ separated at their bases and diverge 

 considerably, giving the intervening sinus a deep basin shape. The 

 distance from tip to tip of the branches is the same as the entire length 

 of the maxilla. 



The proboscis is long and of medium width, with nearly parallel 

 sides. The first maxillipeds are long and slender; the terminal joint 

 carries a small flattened spine on its anterior border at aljout the 

 center. The two terminal claws are very uneven in length and both 

 have serrated flanges along their sides. The second maxillipeds are 

 small and rather weak; the terminal claw is a little more than half the 

 length of the basal joint and strongly curved, with a small and weak 

 accessory spine on its inner margin. 



The furca is very large and wholly unlike that of an}" other known 

 species. It is almost as wide at the tip as it is long, but is contracted 

 to less than half that width at the base, giving the entire appendage 

 somewhat the shape of a thick-stemmed wineglass. The sinus 

 between the branches reaches nearly to the center and has a broad U 

 shape, with the sides parallel. 



The secondary branches are narrow and acuminate, and the sinus 

 between them is triangular and cut in as deeply as the central one. It 

 thus differs markedly from the furca of Mjjpoc/lossl and appendicu- 

 latwi, the only other species in which the furca is doubly bipartite. 

 In lu])j)(>(jlomi the central sinus is triangular and its sides approach 

 each other rapidly and almost touch at the tips. The secondary' 

 l)ranches are laminate and sipiarely truncate at the ends. In ajypen- 

 dtculatui^ the secondary sinuses are not more than a ver}" small fraction 

 of the length of the central sinus. 



