30 ACARIDEA. 
spots and some bristles. Mandibles long and slender, the branches of the chele apparently 
deeply denticulated. Anterior pair of legs rather short, without claws, their second and 
third joints irregularly denticulated ; the posterior pair of legs longer than the others. 
I found one example of this species in a decayed chichique-fruit in the woods near 
Retalhuleu in June 1880. It is nearly allied to the European U. cassidea, Herm. 
4. Uropoda centro-americana, sp.n. (Tab. XVII. figg. 1, la-1f; 2, 2a, 
2 6, nymph.) 
Qyuv. Corpus depressum, oblongo-ovoideum, antice inter secundum et tertium pedum par oblique subtrunca- 
tum, ita ut pars anterior scuti dorsualis in angulum obtusum protrahatur. Superticies dorsualis plana, 
marginem versus declivis, foveolis numerosis cribrata, ex quibus setule breves enascuntur, colore brunneo 
claro (in desiccato animalculo), minus nitente. Pedes omnes unguiferi, sat breves. Articulus ultimus 
primi paris pedum setis numerosis ornatis, inter quas una longissima juxta ungues sita, ungues in manu- 
brio longo gracili inserti, graciles. Articulus ultimus ceterorum parium pedum setulis sparsis atque 
spinis duabus juxta ungium pediculum armatus, brevis. Palpi breves, setigeri, in articulo penultimo 
seta longa, bifida. Palpi maxillares bidentati. Sub apice anteriore scuti dorsualis setule dus in- 
serte. Mandibule graciles, chelarum brachia fere longitudine squales, dentibus paucis et obtusis in 
margine interno undulata. 
Long. 1 millim.; lat. 0-6 millim. 
Hab. Nicaracua, Chontales (Janson). - 
Body (of the young female) depressed, oblong, its anterior margin forming a somewhat 
obtuse angle; dorsal surface even, marked with numerous grooves, out of each of which 
a short bristle arises; the colour, in dry specimens, a clear reddish-brown, not very 
shining. Legs rather short, all of them bearing claws: on the tarsi of the first pair 
the claws are fixed on a sort of slender petiole and surrounded by numerous long hairs, 
one of which is very much longer than the others; the tarsi of the second, third, and 
fourth pairs bear short bristles and two incrassated spines at the base of the petiolus of 
the claws. Palpi short, bearing numerous long bristles on their last joint; on the 
inner side of their third joint there is a long, projecting, pinnate hair. Mandibles 
slender, their chele small, blunt at the top, bearing on the inner edges of the brachia 
four or five obtuse teeth. 
(N.B.—Adhering to the posterior abdominal segments of a Guatemalan specimen of the 
Coleopterous genus Atractocerus I found numerous nymphs of a Uropoda (figg. 2, 2a, 26) 
which I am inclined to identify with the above-described U. centro-americana, as they 
have most of the characters in common, except some which may be the result of the 
differences of the respective stages of development. These differences are as follows :— 
Body flat, oblong, not so distinctly angular on its anterior margin, yellowish, trans- 
parent, the hairs on the dorsal plate apparently a little longer and less numerous; the 
incrassated spines of the legs (which in the adult are placed at the base of the claw) 
attached to the side of the tarsus, one of them on the false joint and the other on the 
tarsus proper. Length 0-4, breadth 0:25 millim. 
Clusters of these nymphal forms attach themselves by viscous threads to the skin of 
