SCIENTIFIC SURVEY. 



185 



spring and fall. They can be raised, and their habits observed in 

 Aquaria. 



Gyrinidce, Whirl-gigs, are easily distinguished by their form and 

 habits, being always seen in groups, gyrating and circling about 

 on the surface of pools, and when cau^^ht giving out a disagreeable 

 milky fluid. Their short antennae, short mandibles and two pair 

 of ocelli, and bluish black colors, distinguish them from other 

 aquatic beetles. Like the previous family, upon being disturbed, 

 they suddenly dive to the bottom, holding on by their claws to 

 submerged objects. They carry a bubble of air on the tip of their 

 abdomen, and when the supply is exhausted, they rise for more. 

 The larvae resemble a small centipede, with lateral ciliated fila- 

 ments, serving as organs of respiration. 



Hydrophiloe. Carnivorous as larvae, but when beetles, vegetable 

 eaters, and living on refuse and decaying matter ; this family unite 

 the habits of the previous mentioned families, with those of the 

 scavenger silphidae, &c. They are aquatic, small, convex oval, 

 or hemispherical beetles. Their antennae are short, and their palpi 

 are long and slender. The allies of the genus Sphcerium, live in 

 excrements of herbivorous animals. 



Silphidoe, Carrion or Sexton beetles, are useful in burying 

 decaying bodies in which they lay their eggs. Smaller species 

 live in fungi, &c. ; other genera live only in caves ; Gafops inhab- 

 its ants' nests. Another genus Braihinus, has been found from 

 Lake Superior to Nova Scotia, about grass roots in wet places, and 

 are small shiny insects of graceful form, according to Le Conte. 



The group is distinguished by the knobbed antennae. Their 

 larvae are crustaceous, flattened, the sides of the body often serrated, 

 black and of a foetid smell ; or those immersed in the midst of their 

 food have weak limbs and soft bodies. The beetles can be caught 

 on the wing in warm spring days, or taken at light in summer. 

 By placing dead birds and small mammals, &c. in favorable places, 

 they are allured in considerable numbers. 



By the Scijdmaenidae which are minute oval shiny brown insects 

 found under stones near water, in ants nests and under bark, we 

 pass to the PselapMdae, with short elytra, much broader than the 

 prothorax and head, with clavate antennae, and palpi nearly as 

 long, which are found in spring in moss, or swept from herbage or 

 taken while on the wing, we come to the Slaphylinidce or Rove 

 beetles, which are long, linear, black, with remarkably short elytra, 



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