578 PROCEEDINGS OF THE NATIONAL MUSEUM vou 94 



j *. Suction cups normal size ; supporting ribs made up in 

 female of 12 to 14 imbricated plates with a rectangular 

 basal segment ; larger respiratory area same width 



throughout fuscus 



ff '-. Swimming legs with flagella. 



/i-\ Anterior hook on first antenna, broad spine at base and 

 broad postantennal spine ; ventral surface of maxilliped 



with spinous pads and boss on basal plate pug'ettensis. 



h'. Anterior knob on first antenna ; no jwstantennal spine ; no 

 spinous pads on maxilliped but boss on basal plate; dorsal 



ribs of carapace branched anteriorly japonicus (p. 558) 



</*. Basal maxillary plate lobed. 

 e^. Lobes of maxillary plate truncate ; anterior hook on first antennae ; 

 ribs of suction cups made up of rods. 

 f. Lobes of maxillary plate parallel, squarely truncate ; ribs of suction 

 cups made up of 3 rods ; posterior respiratory area deeply notched 

 on inner margin, posterior end much wider than anterior. 



laticauda 

 f. Lobes of maxillary plate very divergent, truncate in female, 

 rounded in male; ribs of suction cups with 4 or 5 rods; pos- 

 terior respiratory area not notched and same width throughout. 



reticulatus 

 e.* Lobes of maxillary plate not truncate. 



f. Postmaxillary spines missing; proximal lobe of maxillary plate 

 m(jre widely separated than the other two ; ribs of suction cups 

 made up of 16 to 18 segments singly imbricated; abdomen of 

 male 3 times as long as wide, testes 10 times as long as wide ; 



third and fourth basipods in the male modified funduli 



p. Postmaxillary .spines missing; neither lobes nor teeth on the basal 

 maxillary plate ; ribs of suction cups made up of 18 to 19 seg- 

 ments doubly imbricated; abdomen of male one-eighth longer 

 than wide; testes 3 times as long as wide; male legs not 



modified latus* (p. 560) 



f. Postmaxillary spines missing ; teeth on basal maxillary plate 

 long and evenly spaced : ribs of suction cups made up of 14 to 15 

 segments not imbricated; lobes of abdomen fringed with short 



hairs nattereri* (p. 573) 



f. Two pairs of postmaxillary spines pi'esent ; lobes of basal maxil- 

 lary plate broad, truncate; ribs of suiCtion cups made up of 2 

 rods shaped like a cane with a curved handle, handle of both 

 rods proximal ; anterior respiratory area small, triangular. 



violaceus 

 6'. Smaller respiratory area mesial to larger or in an anteromesial notch of 

 latter, 

 ci. Spine present at base of first antenna. 



(P. Three postantennal spines in a row on each side of midline. 



e". Smaller respiratory area anteromesial ; ribs of suction cups 2-seg- 



mented, distal segment a third as long as basal, blunt; anterior 



peg on fourth male basipod conical, posterior process broadly 



rounded americanus 



