62 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 126 
Mandible (fig. 24f) rodlike, 4-parted, distalmost part curved inwards, 
inner surface with 12 denticulations. Postantennal process (fig. 24/) 
situated posterior and lateral to antenna base, consisting of heavily 
sclerotized clawlike projection with 2 nodules proximally, third present 
just posterior to base of projection; nodules each bearing single, large, 
hairlike process. Postoral process (fig. 24f) dagger-like, immediately 
adjacent to maxilule. Maxillule (fig. 24f) situated lateral and slightly 
posterior to mouth cone base, consisting of node bearing 2 short and 
one long seta-like projections. Maxilla (fig. 24g) 2-sezmented, situated 
lateral and slightly posterior to maxillule. First segment slightly more 
than three-fourths the length of second, proximal articulation and 
muscle attachment surface directed at sharp angle to axis of segment. 
Second segment rodlike, bearing small, horsehoe-shaped membrane 
from medial inner surface and 2 saber-shaped terminal processes. Inner 
terminal process approximately twice the length of outer, both with 
fine membrane along inner and outer surfaces. 
Maxilliped (fig. 24h) small, 2-segmented, situated posterior and 
slightly medial to maxilla base. First segment narrow, with small, 
spikelike projection from proximal posterior surface. Second segment 
rodlike, distinct from short, clawlike terminal process, with setule-like 
accessory process on distal inner surface. Sternal furca (fig. 242) 
situated on median longitudinal axis of body posterior to maxilliped 
bases. Basal region of furca subconical, tines flattened, chisel-shaped 
distally. 
Thoracic legs I-III biramous although endopodite of first leg 
rudimentary. Fourth thoracic leg uniramous, 3-segmented. For na- 
ture and armature of legs, see figures 25a—f and table 10. 
Discusston.—Caligus pseudokalumai most closely resembles C. 
kalumai Lewis (1964a) recorded from Acanthurus guttatus from the 
Hawaiian Islands. The relatively minor differences between the two 
species include the following: 
1. The cephalothorax is more elongate in C. pseudokalumai, and the 
posterior median cephalothoracic region projects posteriorly past the 
posterior lateral cephalothoracic regions more than twice as far as it 
does in C. kalumai (0.36 mm to 0.16 mm). As a percent of the length 
of the cephalothorax, this equals 12 and 9 respectively. 
2. The postantennal and postoral processes as well as the sternal 
furca are bulkier and more heavily sclerotized in C. kalumai. Even 
with this, however, the 3 nodules associated with the postantennal 
process each bears a single large (in comparison with other species 
of the genus), hairlike process (not 2 as stated in Lewis, 1964a, p. 
175) as do those in C. pseudokalumai. 
3. The first segment of the endopodite of the second thoracic leg 
bears a tuft of plumosities in C. kalumai but does not in C. pseudo- 
