the spermatogonia
(figs. 224 and 230), and in the first spermatocyte division an odd
chromosome (_x_) which is in each case the smallest. In the first of
these Elaters, the female somatic number was determined to be 20 (fig.
229). In the second Elater the pairs of second spermatocytes, containing
9 and 10 chromosomes respectively in the two cells, were in nearly every
case connected as shown in figure 235, one pair of chromosomes not
having separated completely in the first mitosis. Of _Ellychnia
corrusca_ (family Lampyridae) only the spermatogonial equatorial plate,
containing 19 chromosomes (_x_, the odd one) is given, as no material in
maturation has yet been obtained, and a comparative study of the germ
cells of the Elateridae and Lampyridae will be made as soon as suitable
material can be secured.

In addition to the species of Coleoptera described here, two others,
_Coptocycla aurichalcea_ and _Coptocycla guttata_ have been studied by
one of my students and the results published elsewhere (Nowlin, '06). In
both an even number of chromosomes (22, 18) was found in the
spermatogonia, one being very small and forming with a larger one an
unequal pair which remained condensed during the growth stage and
separated into its larger and smaller components in the first
spermatocyte mitosis. The result of maturation, as in the other species
here described and in _Tenebrio molitor_, is dimorphism of the
spermatozoa. The method of synapsis in Coptocycla is like that described
for _Chelymorpha argus_.

HEMIPTERA HOMOPTERA.

Aphrophora quadrangularis.

The abundance of Aphrophora at Harpswell, Maine, in June and July, 1905,
suggested that it might be well to examine at least one more of the
Hemiptera homoptera for comparison with the many species of Hemiptera
heteroptera which have been recently reexamined by Wilson ('05, '05,
'06).

The larvae only were collected, as they gave all the desired stages for a
study of the spermatogenesis, and also oogonia and synizesis and
synapsis stages of the oocytes. In the first collections the testes were
dissected out, but the many free follicles break apart so easily that
the later material was prepared by cutting out the abdominal segments
which contained the reproductive organs, and fixing those without
dissection. The same methods of fixation and staining were employed as
for the Coleoptera. Hermann's safranin-gentian method was especially
effective with this material.