398 
PACIFIC SCIENCE, VoL XI, October, 1957 
done by Helen Au Randall, formerly of the 
University of Hawaii. In these figures, the 
scales provided are marked in 10 p, units, 
except for the few marked in 100 p units. 
The latter are drawn with a double base line, 
and also have the total length indicated on 
the scale. 
This is not intended to be an exhaustive 
review of the species assignable to the family. 
While such might be desirable, as a matter of 
fact existing descriptions are so inadequate 
that a thorough review of the group is im- 
possible until all species have been redescribed. 
Only where it was felt that a specific con- 
tribution to knowledge could be made on the 
basis of the descriptive material available has 
mention been made of previously named 
forms. For example, the genus Polyd0'a 
Methlagl is shown to belong in the family, 
at least provisionally, and a brief mention of 
Crossothromhium Womersley, omitted from re- 
cent catalogues, is included to bring it to the 
attention of other workers who might also 
overlook it. 
MORPHOLOGY 
In describing these and other mites, the 
writer has found it useful to develop a system 
of notation of the position of specialized 
setae or other features on the segments of the 
legs and palpi. It is frequently necessary to 
indicate the precise position of these, but at 
present there is no brief, convenient method 
for doing so. The system will be illustrated 
by an example. The position of the seta or 
other structure is stated with reference to the 
proximal and distal ends of the segment. For 
instance, the statement "tarsus II with a 
spikelike famulus at 0.61 pd" means that 
famulus 2 is located at a point 0.61 of the 
length of the tarsus from the proximal end, 
and on the posterodorsal aspect of the seg- 
ment. The terms dorsal, ventral, anterior, and 
posterior, are utilized to express position with 
relationship to the longitudinal axis of the 
legs. The terms lateral and medial are not 
employed, since the meaning of these terms 
is reversed on legs I and II as compared with 
III and IV. The reader should visualize the 
legs as protruding from the sides of the body 
at right angles to the main axis of the body. 
For the sake of morphological uniformity, 
the same orientation should be visualized in 
the case of the pedipalps despite the seeming 
incongruity of the pedipalps of a mite pro- 
jecting at right angles to the median axis of 
the body. The terms preaxial and postaxial 
are in some respects preferable to anterior and 
posterior, in referring to the segments ..of 
appendages, but the writer prefers to use an- 
terior and posterior because the symbols a 
and p are immediately understandable, avoid- 
ing the necessity of using either two-letter 
symbols, or others which are less readily com- 
prehensible. In the following descriptive ac- 
counts, the symbol a following a decimal in 
the designation of the position of a particular 
seta or structure means anterior, p = pos- 
terior, d — dorsal, v = ventral, ad = antero- 
dorsal, pd = posterodorsal, av = antero- 
ventral, and pv = posteroventral. This method 
of notation greatly simplifies the problem of 
precise location of setae, and also makes it 
possible to analyze variation in the positions 
of specific setae. By the use of special graph- 
ical methods it is possible to directly deter- 
mine the positions of the specialized setae 
with ease and rapidity, without the necessity 
of making measurements and converting 
these to decimals. 
In naming the specialized setae of the ap- 
pendages, the writer has adopted the system 
first propounded by Grandjean, beginning in 
1935. The only modification was the addition 
of a system of notations for the several types 
of solenidia found on the legs. The Grand- 
jean system of setal nomenclature is based 
primarily upon the form and physical prop- 
erties of the setae, rather than upon their 
position. The solenidia are thin-walled setae 
showing spiral or annular internal structure 
in most types, although some solenidia do 
not show any internal structure. Typically the 
