Teredicola typica — Wilson 
273 
sidered When the two appendages were 
dissected together with their surrounding tis- 
sue mass and viewed laterally, the more dorsal 
origin of the mandible and the separate in- 
sertions of the two appendages were clearly 
apparent. 
Preparations of some of these dissections 
made for study of detail under high power 
objectives are particularly instructive as ex- 
amples of distortion due to cover glass pres- 
sure. Figures 17 and 18 are diagrams of two 
examples of such mounts. In each the anterior 
appendage (mandible) and a portion of the 
framework from which it arises, partly overlies 
or underlies the posterior appendage (first 
maxilla) and appears to be attached to the 
latter. The study and illustration of prepared 
mounts such as these, in which the two ap- 
pendages lie in a wholly unnatural relation- 
ship, have probably been responsible for or 
have at least contributed to the continuing 
argument as to whether or not Sars (1918) 
was correct in interpreting these two appen- 
dages as the maxilla and its attached palp. 
In this instance, however, if there were a real 
attachment between these two appendages, 
the condition in Teredicola would represent a 
reversal of the Sarsian interpretation inasmuch 
as the smaller anterior appendage (the maxilla 
of Sars) would be attached to the larger pos- 
terior appendage (the palp of Sars). The re- 
duced anterior appendage of Teredicola cor- 
responds structurally to the main body of the 
maxilla of Sars by virtue of its modified apical 
armature. The larger posterior portion cor- 
responds in its simple setal armature to the 
so-called palp of other poecilostomes. Quite 
obviously, if the condition shown in Figure 
17 were realistic, it would negate the argu- 
ment that the first free appendage must be 
called a maxilla because its armature resembles 
portions of that found in some other copepods. 
It may be useful to other workers to include 
here some personal remarks about the require- 
ments and techniques of study of the oral 
area of poecilostomes. It seems to me that, 
in addition to knowing the details of isolated 
appendages, it is instructive to know their 
relationship to one another in situ , and to the 
other structures and the framework of the 
mass. At least schematic drawings of the 
whole oral area should be included in de- 
scriptions of new or little known genera. In 
species in which the cephalic segment is 
tumid, as it is in Teredicola typica , it is neces- 
sary to remove the buccal mass in toto from 
the ventral face, not only for its own study, 
but for dissection of appendages. Attention 
is drawn here to the micro-shears designed 
by C. S. Wilson (1953), because they greatly 
facilitate work with such fleshy masses. 
In poecilostomes with extremely compact, 
fleshy, or protuberant masses and highly 
modified appendages, I have found it essen- 
tial for personal understanding of the rela- 
tionships of the appendages to the buccal 
mass and to one another to study unmounted 
material and to alternate the study between 
the stereoscopic and compound microscopes. 
Although it is not possible to secure high 
enough magnification for study of detail with 
the stereoscopic microscope, it does give the 
third dimensional, natural depth that is lack- 
ing in views under the compound, and con- 
tributes greatly to interpretation. 
SYSTEMATIC POSITION 
Teredicola has been referred to the family 
Clausiidae (M. S. Wilson and Illg, 1955) in 
a revised and restricted definition limiting the 
family to the genera Clausia , Seridium , Mesni- 
lia , Teredicola , and the inadequately known 
jR hodinicola. The close relationship of this 
family to the Clausidiidae is pointed out, and 
the intermediate condition of the apical arma- 
ture of the mandible of Teredicola used to 
suggest that further study may lead to a 
merging of the two families or establishment 
of an inclusive, higher category. 
It is not necessary to discuss the classifica- 
tion further since the matter has been dealt 
with in the previous paper. In assigning other 
species to Teredicola , it will probably be found 
