16 ACARIDEA. 
broad longitudinal stripe of a rosy light-red occupies the middle of the dorsum, and 
three unequally placed transverse lines of the same colour run across the back. Palpi 
longer than the rostrum; the second joint the longest, the third and fourth joints very 
short; the fifth joint shorter than the second, obliquely truncate at the apical end, 
where it bears two long stiff sete, the inner seta being shorter than the outer one. 
Mandibles very long, broad at their base, narrowing gradually towards the end; chele 
very small, their immovable tooth acute, falciform, the movable one broad, truncate at 
the end. Skin soft, showing under the microscope very fine and densely-set wrinkles. 
The dorsum bears several stiff setee arranged in two longitudinal rows. The point of 
the epistoma has a small brush of short hairs beneath, which latter, by a narrow median 
interstice, are divided into two. The hairs of the palpi and dorsum are only most finely 
fringed, those on the legs being quadrifid. Claws of the tarsi broad, curved; the false 
(third) claw with a short-haired brush. 
This pretty Bdella lives amongst dead leaves in the hedges and gardens of the city of 
Guatemala. 
Note.—On the 10th of July, 1880, I found the larva of an Acarid adhering to one of 
the fore legs of a large Elateroid beetle, Chalcolepidius, sp., in the woods near Retalhuleu, 
and some days later a stripped-off skin of the same kind of larva on the bark of a tree. 
This larva, which I have figured under the doubtful name of della, sp. (Tab. III. 
fige. 3-3.d), is 0°5 millim. long, and reddish-yellow in colour, with an ovoid abdomen, 
which is attenuated towards the rostrum (thus forming a sort of collum, on which 
a stout rostrum is inserted); the shoulders a little prominent, rounded, and with a 
large black eye-like spot on each side near the margin; the dorsal surface of the soft 
abdomen beset with several transverse rows of short, quadrifid, somewhat clavate setee, and 
the skin densely and finely wrinkled. The palpi four-jointed: the basal joint short, the 
second thick, the third narrow, cylindrical, the fourth bearing a falciform claw and a 
straight appendicula (the latter resembling that of the true Trombidia); and with a few 
pinnate hairs spread over the surface, more numerous hairs adorning the appendicula. 
Mandibles long, consisting of a large, broad, basal piece, which is attenuated rather 
suddenly into a long, narrow branch, the latter bearing on its top an extremely small 
tooth. Legs long, slender, with two curved claws and a pinnate false claw. 
Prof. G. Canestrini and Prof. F. Fanzago give in their excellent treatise “ Intorno 
agli Acari Italiani” (Atti Soc. Pad. v. 1877) the figure (tab. 4. fig. 1) and description 
(pp. 70 et seg.) of an Acarid larva, which bears a strong resemblance to the above- 
described larva from Retalhuleu, from which it differs, however, in the want of eyes 
and of a false claw. The learned authors are of opinion that their larva is that of 
Rhyncholophus electoralis, Koch, or of an allied form. The species from Retalhuleu 
has in common with Rhyncholophus only the short quadripinnate hairs of the back and 
