2, PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
assistance given to him by James Coatsworth, John Shoup, and 
David Au, who were serving as research assistants at the Eniwetok 
Marine Biological Laboratory during the periods when the collections 
were made. Finally, the author appreciates the help given to him by 
members of the Division of Crustacea of the Smithsonian Institution 
during the time of final examination of the specimens in the collections. 
Metuops.—The external surface, gill cavities, buccal cavity, and 
nasal cavities of the hosts were examined for parasitic copepods. 
Copepods collected were killed and preserved in 95 percent ethyl 
alcohol. Specimens to be drawn or dissected were placed in 85 per- 
cent lactic acid to clear and soften them, stained with Chlorazol 
Black E dissolved in 85 percent lactic acid, and then placed in benzyl 
alcohol for final clearing and for dissection and drawing. 
Drawings of the entire animal were made from specimens placed 
in benzyl alcohol and covered with a cover slip, supported so that 
the shape of the organism was not distorted. A camera lucida was 
used in making the drawings. The appendages and processes were 
TaBLE 1.—Armature of hypothetical thoracic leg shown in figure 1 
Inter- Protopodite Exopodite Endopodite 
Leg | Surface 0 Ga] | Dae eee Se eee ae ee ee ee 
Plate 
2 1 2 3 1 2 3 
Outer m,h,rh,r r,D,d,dh H fH,Z,mH, C c mp’,mp,Q 
dmH. 
Inner a,SSS,S, e,fm,H CE Cl,cl,dH Pp p,p’ 2PL@? 
dm,fm 
drawn in situ or were removed and mounted in either Hoyer’s mount- 
ing medium or a 1:1 mixture of Turtox’s CMC-10 and CMC-S. 
Measurements were made with an ocular micrometer on specimens 
softened in lactic acid and held loosely in place by a cover slip sup- 
ported by spacers. 
In the figures, the 2 and & signs are used separately under each 
drawing to indicate a difference between the appendage or body 
part of the female and that of the male. The symbols are used to- 
gether (2 o) to indicate the similarity of the appendage or body part 
in both sexes. In the latter case the sex of the specimen from which 
the drawing was made is indicated by a line under the appropriate 
symbol. 
TrerMInoLocy.—The term “cephalothorax” is used to indicate a 
condition in which one or more of the thoracic segments are fused with 
the cephalon. The maxilliped-bearing segment is considered as the 
first thoracic segment. The term ‘‘pedigerous segment” is used to 
indicate a leg-bearing thoracic segment, while the terms “free thoracic 
