FOLSOM: MOUTH-PARTS OF ANURIDA MARITIMA 143 
number, some thinking this is three, while others place it as high as 
seven ; three or four being, perhaps, the figures at present most in favor, 
though Viallanes, who has recently discussed the subject, considers six, 
the number suggested by Huxley, as the most probable. Cholodkowsky 
is of a similar opinion.” 
Packard (’98, p. 54) gives six : — 
Preces oR REGIONS 
NAME OR SEGMENT. OF THE HEAD-CAPSULE. 
APPENDAGES, ETC. 
. Ocellar 
(Protocerebral). 
Epicranium, ante- 
rior region with 
the clypeus, la- 
brum, and _ epi- 
pharynx. 
Compound and sim- 
ple eyes (ocelli). 
Pre-oral 
in early embryo. 
. Antennal Epicranium, includ-} Antenne. 
Post-oral 
(Deutocerebral). 
. Premandibular, or 
Intercalary 
( Tritocerebral). 
. Mandibular. 
ing the antennal 
sockets. 
Wanting in post- 
embryonic life, ex- 
cept in Campodea. 
Epicranium behind 
theantenne, gene. 
Premandibular 
appendages 
(in Campodea). 
Mandibles. 
in early embryo. ; ; 
Epicranium, hinder | First maxille. 
edge? tentorium. 
5, First Maxillary. 
Second maxilla, or 
labium.  Post- 
gula, gula, sub- 
mentuin, mentum, 
hypophary nx (lin- 
gua, ligula), para- 
gloss, spinneret. 
. Second Maxillary, 
or labial. 
Occiput. 
Upon anatomical grounds, different observers have recognized from 
one to seven head segments. As mentioned by Packard (98, p. 50), 
Burmeister found but two; Carus and Audouin three ; MacLeay, New- 
Huxley (’78, p. 343) 
said: “It is hardly open to doubt that the mandibles, the maxille, and 
the labium answer to the mandibles and the two pairs of maxille of the 
crustacean mouth. In this case, one pair of antennary organs found in 
the latter is wanting in insects, as in other air-breathing Arthropods, 
and the existence of the corresponding somite cannot be proved. But if 
it be supposed to be present, though without any appendage, and if the 
man, and Newport four ; Straus-Durckheim seven. 
