522 
THE STUDY OF INSECTS. 
ed in our fauna by two species of Amphizoa (Am-phi-zo'a), 
which occur in Northern California, Utah, and Vancouver, 
clinging to logs or stones under the surface of streams. 
In these beetles the metasternum is truncate behind, not 
reaching the abdomen, and has a very short antecoxal 
piece. 
Family Haliplidas (Ha-lip'li-dae). 
The Haliplids {Hal'i-plids). 
This family includes a few species of small aquatic beetles, 
which are oval, more or less pointed at each end, and very 
convex. The wing-covers have rows of punctures, and the 
hind coxae are greatly expanded so as to conceal the 
basal half of the hind femora and from three to six of the 
abdominal segments. 
These beetles are not uncommon in ponds and streams, 
but they swim poorly. Only three genera occur in this 
country. In Brychius (Brych'i-us), which is represented by 
one species from California, the prothorax is quadrate; in 
the other genera it is narrowed in front. In Haliplus (Hal'- 
i-plus) the last segment of the palpi is small and awl-shaped; 
in Cnemidotus (Cnem-i-do'tus) it is longer than the’third seg¬ 
ment, and conical. 
The larvae are aquatic, occurring near the shores of 
ponds and streams and in other damp places. The body is 
rather slender; each segment except the head is 
furnished on the back with fleshy lobes with spiny 
tips, which vary greatly in size in different species; 
and the last segment bears a long tapering appen¬ 
dage. Figure 629 represents a larva of this family, 
which we found in large numbers in a pond swarm¬ 
ing with Cnemidotus; it probably belongs to this 
genus. The ia* /ae of several species of Haliplus 
629. are figured by Schiotde, but in each of these the 
caudal appendage is forked. 
