52 NEW-YORK FAUNA — CRUSTACEA. 
Color, blackish brown; cinereous on the edges. Three dorsal lines of alternate yellowish 
subquadrate spots. Tail with two or three small yellowish spots on each side at the base. 
Length, 0°4. 
This is also known under the name of Sow-bug, and is found in similar situations with the 
preceding. 
(EXTRA-LIMITAL.) 
P. nigra, Say. (O. granulatus, Lam.? Vol. 2, p. 354. Ed. Brux.) Very rough with elevated 
granules. Last caudal segment margined behind with abbreviated lines. Color, black, immacu- 
late. Length, 0°3. This is found in Pennsylvania, and, according to Dr. Gould, in Massachu- 
setts. 
P.lavis? Latr. (Govtp, l.c. p. 337.) Body smooth; caudal appendices larger than in the preceding. 
Color, dark ash, varied with soiled yellowish. 
GENUS ARMADILLO. Latreiile. 
Habit and many of the characters of the preceding. Outer antenne of seven joints ; inner 
obsolete. Feet fourteen. Caudal appendices not prominent. Roll themselves up into a 
complete ball. Terrestrial. 
ARMADILLO PILLULARIS. 
Armadillo pillularis. Say, Jour. Acad. Nat. Sciences, Vol. 1, p. 432. 
A. id, Gov cp, Invertebrata of Mass. p. 336. 
A. pustulatus? Dxsm. Consid, Gen. pl, 49, figs. 6 and 7. 
Description. Body minutely punctured. Caudal segments slightly smaller than those of 
the body. 
Color. Dull lead-color, with three lines of large yellowish spots above. Posterior margin 
of the segments light colored. 
Length, 0°5. 
This is known under the name of Pill-bug, from its form, in a contracted state, completely 
resembling a pill, and by this alone it is at once distinguished from the preceding genera. It 
casts its shell once a year at least, and these are frequently found under stones and boards in 
fields which have been their habitual resort. It appears in its markings to be closely allied 
to the European A. pustulatus of Dumeril, or variegatus of Lamarck; but I have had no 
opportunity of making a direct comparison. 
It is here, at the end of this order, that we arrange the Brongniarta trilobitoides of Dr. 
Eights (Serolis id. of Audouin and Edwards, Arch. Mus. 1841, p. 29), found off the coast 
of Patagonia, and which appears, with the three other known species, to form a passage to the 
