188 ZOOLOGY. — 
attains a length of three inches, and is sufficiently strong to kill small fish 
and frogs. Dr J oseph Leidy has given the anatomy “ind characters = 
several Now th American species in the Journal Acad. Nat. Sci. . 
Fam. 10. Galgulide. Galgulus oculatus is a small North American 
insect, with an oval, depressed form, a broad head, and pedunculated lateral 
eyes. It may be seen during the day running along the grassy and sandy 
shores of rivers, but it is not aquatic, although it can swim to the shore if 
thrown into the water. It has the power of leaping a few inches, although 
the feet do not present saltatorial characters. When pursued they do inet 
endeavor to escape by flight. 
Fam. 11. Hydrometride. The members of this family live upon the 
surface of the water, over which some of them move with great rapidity. 
Hydrometra moves maition slowly over the surface, with the body elevated 
above it. The ordinary boat-shaped species, with four of the feet adapted 
to locomotion, belong to the genus Hydrometra. The larva of this genus 
has the abdomen very small, and as this is a characteristic of the corre- 
sponding oceanic genus /alobates, it sustains Professor Agassiz’s view that 
freshwater forms are higher than marine ones. alobates being rarely 
found with the wings developed, Westwood thinks they are not to be 
considered as imagos, especially as the abdomen is small; but an extension 
of the views of Agassiz affords a more satisfactory explanation. Many | 
individuals of Gerris, which seem to be perfect, are without wings, and 
seem never to acquire any. 
Fam. 12. Leptopide. This is a small family with the body oval and 
depressed, the eyes large, the feet slender, and the rostrum long. ‘These 
insects are small and active, running and flying along the margins of 
water. The principal genus is Salda, improperly named Acanthia by 
Latreille, a name used previously by Fabricius for the Cimew lectularius. 
This family is named Pzpari by Burmeister. 
Fam. 13. Reduwiude. This family includes active predaceous species 
with a short, stout rostrum, sufficiently strong to pierce insects with a 
tolerably hard integument. The head is narrow behind, forming a kind of 
neck, the eyes are prominent, and there are two stemmata. The North 
American Arilus novenarius, Say, Am. Ent., has the pronotum arched 
above, and notched like the cogs of a small wheel. ‘The puncture of these 
insects is:somewhat poisonous. 
Fam. t4.Tingide. The species of Tingis have a small body with’ the 
wings strongly reticulated, and a membranous expansion upon each side 
of the prothorax. They move very slowly, and are found upon leaves, the 
juices of which they suck in all their stages. It is probable that the larve 
do not move from their first station. Syrtis is also very torpid in its 
movements ; it lives upon trees, and probably feeds upon insects, as the 
anterior feet are very stout, and apparently raptorial. The genus Acanthia, 
first separated from the Linnean genus Cimew by Fabricius, includes the 
bedbug, Acanthia lectularva (pl. 80, fig. 67). Amyot and Serville state 
that the name Acanthia, Fabr., 1776, must stand, being the first given after 
the dismemberment of the old genus Cimex, and on this account they 
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