142 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
he identified were found, and made a number of more or less com- 
plete pencil sketches, especially of the species he considered new. 
But he wrote no descriptions of his new species and did not compile 
notes of any kind. He then ceased work upon the Albatross collec- 
tion and turned back to the completion of a report he had previously 
begun upon the copepods of the plankton collected during the scien- 
tific expeditions of the Prince of Monaco. A preliminary list of 
the species in this Monaco plankton had appeared in two bulletins 
of the Monaco Oceanographic Museum in 1905, with brief descriptions 
of the new genera and species, but no figures. The completed mono- 
graph was published in 1925, preceded during the previous year by 
an atlas of plates (see p. 144). 
That Sars’ work upon the Albatross collection followed his pre- 
liminary list of the Monaco copepods and preceded the publication 
of his final monograph is seen in the following facts: When the 
Albatross copepods finally came into possession of the present author 
many of the vials contained labels in Sars’ handwriting. In nu- 
merous instances the generic and specific names on these labels cor- 
responded exactly with those given in the Monaco preliminary list, 
though the latter were entirely changed in the final monograph. In 
fact, some of the changes were made after the publication of the 
plates and prior to the appearance of the text, so that we find a 
copepod figured under one name in the plates and described under 
a very different name in the text. 
For some reason Sars never resumed work upon the Albatross cope- 
pods, and after his death [in 1927] the entire collection was returned 
to the United States National Museum, together with Sars’ identifica- 
tions, pencil sketches, and records of stations, which were courteously 
made available by the Oslo Museum. All these were then submitted 
to the present author for verification of the species already identified, 
completion of the identification, listing, and recording of the col- 
lection, and descriptions of the new species. The present report is 
the result of these labors. 
COMPLETION OF SPECIFIC CHARACTERS 
It often happens that a plankton sample yields but a single sex, 
more rarely a single specimen upon which to establish a new species. 
If the types are females the new species may at once be accepted as 
valid, since the female in marine copepods, wherever possible, is selected 
as the primary, or holotype. Such species, though valid, are incom- 
plete, since the male characters of the species are lacking. In species 
based on the male alone there is always the possibility that the type may 
prove eventually to be the missing sex of a species described from the 
