574 OPILIONES. 
1. Hernandarioides plana, sp. n. (Tab. LIV. figg. 1, 1a, 2.) 
Type, 2, in coll. Godman & Salvin. Total length 6 millim. 
The general characters have been described in the generic diagnosis. Legs iii. and iv. are slightly stouter 
than i. and ii., covered sparingly with minute tubercles, becoming larger and more cuspulate on iv. 
Colour entirely yellowish-grey. 
Hab. Panama, Bugaba (Champion). 
METAPACHYLWUS, gen. nov. 
Type M. gracilis, sp. n. Mexico. 
Tarsal segments, i. 5; ii. 8; iii. 5; iv. 6. Eye-tumulus with a single median, slender, sharp horn, curving 
slightly forwards. Scutum with five transverse grooves; segments 2, 3, 4, 5 each with a median pair of 
small tubercles, 6 (the first free segment), 7, 8 with three, and 9 with two small tubercles. Palpi 
scarcely as long as the body; femur with two basal spines; tibia and tarsus with a pair of spines on 
each side. Tarsal claw of palpus about half as long as the tarsus. Legs slender, 4, 2, 3, 1, subsimilar, 
those of the fourth pair much the longest, more than twice as long as the second pair. Coxa iv. only 
slightly enlarged. Tarsal claws of iii. and iv. with an inter-basal process. 
A single species only of this genus occurs in the collection. 
1. Metapachylus gracilis, sp.n. (Tab. LIV. figg. 2, 2 a-d, .) 
Type (2 ?) in coll. Godman & Salvin. Total length 2:5 millim. 
The body of this small Opilione is subglobular and of a golden-brown hue, the palpi and mandibles being 
pale yellow. Legs unarmed. Other characters will be found under the generic diagnosis. 
Hab. Mexico, Teapa (H. H. Smith). 
One specimen. 
Fam. ASSAMIOIDA. 
Assamioide, Sérensen, Nat. Tidssk. xiv. p. 595 (1884). 
No sterno-coxal lobe on leg ii. Palpi variable, very similar to those of the Gonoleptide, but short and very - 
stout; the tibia and tarsus fringed with sete or stout spines having an enlarged base. Spiracles 
conspicuous. Seutum with five deep transverse stri# (Sdrensen gives one only). Terminal claws of 
tarsi iii. and iv. without interbasal process. Eye-tumulus much developed, forming a large conical horn, 
with an eye on each side close to its base. Segments of tarsi i. from three to six. Coxa iv. only slightly 
larger than the rest. 
The species here included in this family are nearly allied to Mitraceras and Conomma, 
but they differ sufficiently from these, as characterized by Loman, and from each other, 
to merit inclusion in two separate genera. For the sake of comparison, the essential 
characters of Loman’s two genera are included in the table :— 
GENERA. 
A. Segments of tarsus i. 8. Eye-tumulus curving forwards. 
a, Terminal tarsal claw of palpus as long as the tarsus . . . . [Mrrraceras, Loman. | 
6. Terminal tarsal claw of palpus half as long as the tarsus. . . PaRAMITRACERAS, gen. nov. 
