ZOOLOGICAL SOCIETY BULLETIN 



1433 



PK' 





Photograph by Elwin R. Sanborn 



SHARK SUCKERS ON NURSE SHARK 



THE ARMADILLO OR PILL-BUG. 



A Favorite Food of Frog and Salamander. 

 By Ida M. Mellen. 



THE Armadillidium, commonly called "ar- 

 madillo," "pill-bug" and "sow-bug," is 

 often seen near country roadsides and in 

 the woods, especially in the vicinity of fresh 

 or salt water. 



Far from being a "bug," it is a unique crus- 

 tacean, an isopod of the genus Oniscoidea, which 

 exhibits odd and interesting adaptations of a 

 water animal to land life. Like all true Crus- 

 tacea, it possesses gills ; but they are leaf-like 

 and curiously fitted for breathing air. These 

 strange gills, enclosed beneath the abdomen, are 

 provided with air-tubes not unlike the air-tubes 

 through which insects breathe all over their 

 bodies. The young do not pass through the 

 usual crustacean metamorphosis, but are hatched 

 in the form of the adult. 



The pill-bug (Armadillidium vulgare) pur- 

 sues the tenor of its way — an even enough tenor 

 when there are no frogs, toads, or salamanders 

 about — on seven substantial pairs of legs. 

 Found in damp places, and under stones, boards 

 and roots, it is said by some to be a useful little 

 scavenger, subsisting largely on decaying vege- 

 table matter. Others declare that it destroys 

 the roots of plants. 



The name "armadillo" was given it by rea- 

 son of its habit of rolling itself up into a ball 

 when disturbed, in ajjparent imitation of that 

 luckless creature of the South, the armadillo. 

 The latter, in the possession of its bony, outer 

 skeleton, in which it encloses itself for protec- 

 tion, is no less unique among mammals than is 

 its small namesake among Crustacea. But the 

 crustacean is, in this case, shrewder than the 

 mammal; for, whereas the armadillo will allow 

 itself to be very roughly treated rather than 

 uncoil, — and its shell serves for its own roast- 

 ing pan in the ovens of Southern epicures, — 

 the pill-bug, after rolling itself up once or 

 twice and discovering that the enemy is still in 

 pursuit, will abandon the useless trick and seek 

 to escape. 



ARMADILLO OR PILL-BUG. 



