ORDER PtECILOPODA — ARGULUS. . 57 



once by their inferior size. It is also sometimes called the Sauce-pan, in allusion to the 

 shape of its shield, which is frequently used as a bale for boats. They come up on the shore 

 at high water in May, when the sexes are frequently found attached. They are speared at 

 that time in great numbers, and eaten with great avidity by hogs and poultry ; but care must 

 be taken to give them other food for some time previous to being killed, or their flesh will 

 have a rank disagreeable taste. It is even said that this flavor will be communicated to the 

 eggs of fowls which have fed on these animals. When, however, the flesh of this crab is 

 carefully separated from the other parts, and boiled, it becomes a delicious savory food. 

 They crawl slowly along the bottom, and I have never seen them swimming near the surface. 

 When thrown upon their backs, they inflect the anterior portion of the shield upon the poste- 

 rior, and likewise turn it so far back, that with the aid of their tail as a lever, they succeed, 

 after many awkward attempts, in recovering their natural position. They are frequently caught 

 so abundantly as to be used as a manure. 



The geographical distribution of this species on our coast is not yet determined. It occurs 

 from Massachusetts to Virginia, and probably farther south to the Gulf of Mexico, if the fol- 

 lowing, which is supposed by Mr. Say to be probably distinct, should prove to be a mere 

 variety. 



(EXTRA-LIMITAL.) 



P. australis. (Say, Jour. Ac. Vol. 1, p. 436.) Disk five-spined ; three in a longitudinal line, and a 

 smaller one on each side in a transverse line with the anterior spine, and nearer to the elevated lateral 

 angles. Carolina and Florida. 



Genus Argulus, Muller. Body oblong, covered by a rounded oval membranous shield, somewhat 

 flattened, emarginated behind. Feet twelve, of three kinds : the two anterior tubular, sub- 

 hemispherical, adapted for prehension ; those of the second pair biunguiculate ; the remainder 

 natatory, having at their tips two lobes ciliated on their edges. Antennae four, very minute. 

 Two distant eyes. Mouth externally a sucker of a conical shape, directed downwards. Pa- 

 rasitic. 

 A. catostomi. (Dana & Herrick, Am. Jour. Sc. Vol.31, p. 297.) Shell nearly circular, transpa- 

 rent, slightly convex. Eyes compound. Antennas before the eyes ; posterior pair with four joints, 

 one-third longer than the anterior pair, which has but two. Color, light sea-green. Attached to 

 the inside of the gill-cover of a species of Catostomus. Connecticut. 

 A. alosce. (Gould, Invert. Mass. p, 340 and figure. See Pi. 10, fig. 45 of this book.) Shield obcor- 

 date, covering only the first two pairs of legs. Abdomen narrow and half as long as the shield, 

 bearing the next three pairs ; these, as well as the preceding, have long fringed tips. Inferior 

 caudal plates two, and covered by two others which are long and broad. Length, 0*5. Gills of 

 the Alewife, A. vulgaris. Massachusetts 



Fauna — Part 6*. 8 



