ORIBATA. 25 
the cephalothorax and the anterior insertion of the pteromorphe. Pseudostigmatic 
organs moderately large, slightly increasing in size towards the ends, a little recurved 
on the notogaster. No interlamellar hairs conspicuous. . Coxe and femora of the two 
posterior pairs of legs rather flattened. Notogaster not separated from the dorso- 
vertex, entirely hairless. Pteromorphe middle-sized, flexible, semi-transparent, and 
light-coloured ; projecting obliquely forward, and having rounded anterior ends, when 
seen from the side (from the dorsal aspect their anterior ends seem rather pointed). 
Genital plates widely separated from the anal plates, occupying a sort of pentagonal 
area, whilst the anal area is rather circular. Mandibles bearing four blunt teeth on 
each branch of the chele. Anterior margin of the maxilla showing a deep longitudinal 
fissure near the outer edge. 
This species seems to be common and widely distributed throughout Central America. 
I have found specimens of it in Antigua and in Guatemala city, under stones and on the 
moist walls of the house-wells (pilas). It has also been collected in British Honduras 
by M. Blancaneaux, and on the Volcan de Chiriqui by Mr. Champion. One of tke 
dried specimens from British Honduras which I dissected contained about twenty oval 
eggs, of 0°3 millim. length. 
2. Oribata rugifrons, sp.n. (Tab. XV. figg. 2, 2a-2d.) 
Corpus ovoideum, supra convexiusculum, antice attenuatum, postice late rotundatum, nigrum, nitidum, nudum, 
supra sculptura microscopica e rugulis longitudinalibus subtilissimis confecta ornatum, que in cephalo- 
thorace magis conspicus, in notogastro paullulum obsolete sunt. Cephalothorax ab abdomine sulculo 
transversali discretus, valde declivus, conicus, antice late angulatus, simplex. Rostri clypeus a dorso- 
vertice non discretum. Lamelle haud conspicue. Pseudostigmata recondita ; organa pseudo-stigmatica 
mediocria, in animalculo desiccato setiformia, apice incrassato. Sete interlamellares absunt. Tectopzedia 
haud conspicua. Pedes mediocres, colore fusco, setulis et unguibus tribus armati. Pteromorphe longa, 
sat anguste, antice angulatim protracte, rotundate, postice acutiuscule, mobiles: corpori appresse pedes 
omnes obtegunt. Abdominis latera ad recipiendas pteromorphas leviter excavata. Sculptura microscopica 
pteromorphorarum e rugulis radiatim ex insertione sese fundentibus confecta, Lamine anales semilunares, 
genitalibus majores. Laminz genitales ab analibus valde distantes, aream rotundato-pentagonam occu- 
pant. Mandibule crasse, chelarum brachium fixum dentibus 4, brachium mobile dentibus 5 armatum. 
Palporum articulus secundus incrassatus, quintus in medio dentem unguiformem acutum, curvum gerens. 
Long. corp. 0°85 millim. ; lat. max. 0-6 millim. 
Hab. British Honpuras, Belize (Blancaneaux); GuatEMALa, Retalhuleu (Séol/). 
Body ovoid, convex, rounded behind, its anterior end somewhat blunt; black, shining, 
but not polished, without hairs on its dorsal surface, this latter showing a minute sculp- 
ture consisting of closely placed, extremely fine, longitudinal wrinkles, which are more 
distinct on the cephalothorax than on the notogaster. A transverse furrow separates 
the notogaster from the cephalothorax, which is very simply built, conical, ending in a 
somewhat blunt point. Hood of the rostrum forming but one piece with the cephalo- 
thorax. Lamelle wanting. » Pseudostigmata apparently hidden, invisible from above ; 
pseudostigmatic organs in the dried specimens of moderate size, setiform, increasing 
BIOL. CENTR.-AMER., Arachn. Acar., September 1891. E* 
