12 ACARIDEA. 
five distinct spots—three short ones before, and two large, longitudinal, parallel ones 
behind the lateral branches. Legs of moderate size, the first pair the shortest, the 
following pairs gradually longer; all bearing tufts of swimming-hairs and spines of 
varied length, and the fourth and fifth joints at their apical ends with tufts of long 
swimming-hairs arranged in oblique rows; the fourth pair with a row of short spines 
on its lower surface; the claws strongly curved, forming an acute angle. Palpi with 
the second joint thicker than the rest, the fourth joint bearing on its middle an oblique 
setigerous tooth. yes conical, diverging. Stigmata of the genital area numerous, 
about twenty-six on each side, arranged on a semilunar space. 
3. Body somewhat truncate at its anterior margin; dorsal patch limited to the 
posterior half of the back, the anterior half milk-white. Claws strongly curved, both 
of them inserted on a common swollen basis. Stigmata of the genital area numerous, 
about twenty in number, not arranged in a semilunar area as in the female, but rather 
irregularly disseminate on an obliquely transverse, oblong space. The fourth joint of 
the hind legs bears on the middle of its inner side an excavation, the margins of which 
are beset with rows of obliquely set spines or teeth placed opposite to each other. The 
concave edge of the mandibles shows some very small indentations towards the apex. 
The male and female above described were found in a pond in the Vicinity of 
the city of Guatemala. Not having seen them in copuld, nor bred them, I am not 
quite sure that they belong to one and the same species; yet from their general 
appearance, their common habitat, and from the fact that I found no other Nesea, 
except V. numulus, in this pond, I am inclined to think that the above-described 
specimens really belong to the same species. 
2. Nesea numulus, sp. n. (Tab. XI. figg. 2-2 ¢.) 
Q. Corpus orbiculatum, numuli instar valde depressum, antice truncatulum, in margine anteriore utrinque 
tuberculis trinis piligeris juxta oculum instructum; colore fuscescente, opacum, cuticula cribelli instar 
perforatula; macula dorsualis lata, margine exteriore lobato, nigra, in dimidio anteriore maculis claris 
paucis rotundis interrupta, in medio per glandulam dorsualem, latam, fuscam, postice utrinque dilatatam 
divisa. Pedes breves, a primo pari gradatim longitudine crescentes, setigeri, piligeri ; par quartum serie 
spinarum atque seta pinnata ad articuli quarti et quinti apicem subtus instructum ; articulus extremus 
ad apicem subtus subexcavatum. Palpi marginem corporis anteriorem paullulum superantes, tenues ; 
articulo quarto arcuato, dentigero. Stigmata aree genitalis numerosi, circiter triginta in quoque latere. 
Oculi in margine anteriore siti. 
Long. et lat. 0°75 millim. 
Hab. GUaTEMALA, near the city (Stoll). 
Body orbicular, very much depressed, truncate at its anterior margin, the latter 
bearing three small tubercles on each side (under the microscope the skin seems 
to be perforated by densely set little holes, like a sieve); colour brown; dorsal patch 
black, broad, with several transparent brown spots on its anterior half, its exterior 
margins lobate; dorsal gland compact, broad, brown, truncate before, laterally extended 
behind. Legs short, the first pair the shortest, the following pairs gradually longer ; all 
