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PROCEEDINGS OF THE NATIONAL MUSEUM 



antennae are missing on one side of the female ; those from the other side were 

 prepared as a permanent Euparal mount. As is 4-segmented. A permanent 

 mount of the sucking disk was made, but the state of the specimen renders 

 determination of rib segmentation difficult. Basal segments of the ribs are iden- 

 tical with those in all "trilineatus" specimens. In most ribs a count of six seg- 

 ments can be made ; there certainly are not nine small, beadlike, uniform seg- 

 ments per rib. 







Q 



ABDOMEN 



Figure 26. — Method used for measuring Argulus japonicus: AB, total length; CD, maximum 

 width; EF, length of left carapace; GH, length of right carapace; JK, width of abdomen; 

 LM, maximum width of posterior sinus of carapace; NO, length of anal sinus; PQ, length 

 of abdomen; RS, length of posterior sinus of carapace. 



It will be seen that the characters (1), (2), (3), (4), and (7) claimed 

 by Wilson for the type specimen of A. trilineatus are all contradicted 

 by this reexamination of the type deposited by Wilson in the National 

 Museum. The discrepancies between Wilson's description of A. 

 japonicus and the specimens identified by him as A. japonicus de- 

 scribed above are confirmed by Dr. Chace and Mr. Illg. It is clear 

 that Wilson, according to the records on the labels of the specimens 

 in the National Museum, did identify specimens as A. japonicus that 

 showed characters as first enumerated by Thiele as well as the addi- 

 tional features recorded by Tokioka and Meehean. There is no speci- 

 men available that corresponds with either one of the A. trilineatus 

 and A. japonicus descriptions given by Wilson. Until such specimens 

 can be found, the two descriptions published by Wilson must be con- 

 sidered invalid. It is clear that A. trilineatus is synonymous with A. 

 japonicus Thiele. What A. japonicus Wilson (1944) may be cannot 

 now be settled ; it is certainly not japonicus Thiele and may be based 

 entirely on errors of observation. Until specimens answering to the 

 description are found no new name is required. 



