ACARINA FROM THE JUAN FERNANDEZ ISLANDS 571 
We are reminded of this by the Juan Fernandez collection which although 
comprizing only a small portion of the acari of those islands nevertheless con- 
tains at least one very curious form, which is the type of the present genus. 
Diagnosis: Dorsal side completely covered by a white waxy 
secretion, Propodosoma long, pointed, with neck-shaped, constricted 
base. Hysterosoma reniform, much wider than it is long, with con- 
cave dorsal side. Lamelle very thin and broad, almost horizontal 
blades. Pseudostigmata very large, trumpet-shaped, projecting; 
pseudostigmatic organs long, filiform, curved backwards. Rostrum 
sharply pointed, with terminal deep incision. Mandibles very long 
and narrow, with small chela. 
5. Cerocepheus mirabilis n. sp. — Figs. 32-- 41. 
Length 780 »w. Length of propodosoma 340 »., width of propodosoma 
190 wu. Length of hysterosoma 440 », width of the same 560 uw. 
Colour dark chestnut brown. 
Texture dull and rough. The entire dorsal side of the whole body is 
covered by a white waxy matter, so that only the tips of the legs are visible 
from above. This wax is probably secretated through pores which are placed 
at the base of the propodosoma, round the lateral and posterior margin of the 
hysterosoma and between the last pairs of the dorsal hairs (fig. 32). 
Propodosoma. very long and narrow, almost twice as long as it is wide 
at the base. Rostrum sharply pointed and with deep narrow incision (fig. 32) 
which reaches half way to the translamella. The posterior part of the incision 
is surrounded by a horse-shoe-shaped plate of thicker cuticle, with radiating 
striz. Propodosoma distinctly set off from the hysterosoma by a short, neck- 
shaped constriction. 
Lamellz very large, thin, almost horizontal blades which start in front of 
the pseudostigmata from a narrow base, widen suddenly and are then of al- 
most even width throughout, extending forwards with broadly rounded cusps 
which extend almost to the top of the rostrum where they nearly meet. Trans- 
lamella a narrow, thickened ridge. Lamellar hairs inserted on the cusps a short 
distance from their anterior margin, slender and curved slightly inwards, then 
outwards near the top. 
Interlamellar hairs very long, flexible, whip-like, inserted on a level with 
the base of the lamellze on low projections, 
Pseudostigmata of exceptional size (figs. 34) shaped as large trumpets, 
directed horizontally outwards and bent slightly forwards. Their anterior edge 
has a sharp tooth pointing forwards, the posterior edge has a low blade, which 
fits in between two teeth at the anterolateral margin of the hysterosoma, and 
is constricted at the base. 
The interior is shaped like a trumpet, with thin cup-shaped rim narrowing 
gradually and curved sharply forwards at the end. Pseudostigmatic organs 
curved obliquely outwards and backwards where they emerge from the cup, 
rodlike, of even width throughout and slightly pointed at the end. 
