PAGURUS. 
PAGURUS. Fabr., Bosc, Lam., Latr., Leach. 
ASTACUS. Pennant. 
CANCER. Linné. 
Antenne interiores breviores, setis duabus articulatis ; inferiore breviore, filiformi; superiore 
compressa subconica infra pilosa, pedunculus triarticulatus, articulo tertio longiore : 
exteriores setacee longissime multiarticulate; pedunculus 4-articulatus, articulo 
secundo ad apicem supra spina mobili instructo. 
Pedipalpi gemini externi cauli interno articulis quinque exsertis ; articulis 1 et 3 brevioribus, 
2 et 4 longioribus longitudine subequalibus. 
Oculi frontales, spina mobili supra ad illorum basin. 
Pedes decem ; par anticum valdé inequale, majus, didactylum; digitis fasciculato-pilosis ;— 
paria 2 et 3 elongatis, aqualibus unguibus elongatis subcurvatis instructa; paria 4 et 5 
abbreviata, subcrustacea, pilosa, didactyla. 
Thorax membranaceus anticé supra clypeo crustaceo instructus. 
Abdomen membranaceum exarticulatum, elongatum, molle. 
Cauda triarticulata, crustacea, articulo secundo utrinque appendiculato. 
Interior anienne shortest, with two articulated sete; the lower seta shortest, filiform; the 
upper one compressed, subconic hairy beneath; peduncle three-jointed, the third joint longest : 
exterior antenneé setaceous, very long, composed of many joints ; peduncle 4-jointed, the second 
joint with a moveable spine at the upper part of its extremity. Eaternal feetpalpes with their 
internal footstalk having five exserted joints, the first and third joints shortest; the second and 
fourth longest and of equal length. Eyes situated in the front, witha moveable spine at the 
upper part of their base. Legs ten; anterior pair very unequal, larger than the rest, didactyle, 
the fingers with tufts of hair; second and third pairs of equal size, elongate, with subcurved 
elongate claws; fourth and fifth pairs short, subcrustaceous, hairy, didactyle. Thorax mem- 
branaceous, with a crustaceous shield on its anterior part above. Abdomen without joints, 
elongate, membranaceous, soft. Tail triarticulated, crustaceous, the second joint with appendices 
on each side. 
The animals of this genus are commonly denominated Soldier, or Hermit-crabs. Their 
economy Is extremely curious and interesting, and so much so as to have attracted the attention 
of ancient naturalists ; one species is described by Aristotle under the title zapuvoy. 
All the species are parasitic, and inkabit the cavities of turbinated shells. They change 
their habitation during their growth, first occupying the smallest shells, aud latterly those of 
considerable dimensions. They adhere to the pillars of the shells by the appendices situated on 
either side of their tail : and move about with great facility, dragging the shells after them. 
