126 PARNIDA. 
This is a very peculiar form of Parnide, being intermediate in appearance between 
the members of that family and those of the Byrrhide, and really closely connecting 
the two families by many of its characters. It is, however, clearly related to the 
Potamophilini, and should form one of the genera of that very distinct group of the 
Parnide. The clothing of the upper surface consists of very fine, short, erect or only — 
subdepressed hairs; and the under surface has a very dense short pubescence of such a 
character as is commonly found in Byrrhide, in Morychus for example. The antenne 
are widely distant at their insertion, and but little different from those of Potamophilus, 
the basal joint, however, being more elongate and joints 3-11 more simple. The head 
is flexible, and can be much withdrawn within the prothorax ; but when this is the case 
the trophi are still exposed. The prosternum has no distinct chin-piece ; nevertheless it 
projects quite as far forwards, or even a little further than does the pronotum, and is 
somewhat deflexed in front to enlarge the opening for the head; the sides are pecu- 
liarly formed, being divided by a diagonal line, and the portion behind this line 
hollowed for the accommodation of the front legs. The anterior coxe are very deeply 
imbedded and excessively elongate, and possess a large trochanter; they are placed far 
from the front of the prosternum. The mesosternum is very visible, and so much 
advanced in front that it is placed under the prosternum; it is very intimately con- 
nected with the prosternum by possessing a large depression into which is fitted, in the 
most accurate manner, a large prosternal process. The suture in the middle between 
the mesv- and metasternum is obliterated. ‘The'epipleuree are suddenly and abruptly 
narrowed at the level of the hind cox; these latter are very transverse, and scarcely 
longer (interpreting that word as referring to the longitudinal direction of the body) 
internally than externally; they are separated by an elongate, moderately broad 
projection from the first ventral segment. The legs are of the Parnid type, without 
spurs; the tarsi 5-jointed, the four basal joints being short and subequal, the fifth 
equalling the whole four in length. The ventral segments are five in number, the 
second not quite equal in length to the third and fourth together. 
In any discussion of the relation between the families Byrrhide and Parnide this 
insect must play an important part. 
1. Byrrhomorphus vestitus. 
Ovalis, sat convexus, niger, supra pube brevi fusca dense vestitus, equaliter subtiliter sat dense punctatus, 
antennarum basi sordide testacea, pedibus piceis ; subtus pube grisea brevi densissime vestitus. 
Long. 24, lat. 13 lin. 
Hab. Guatemata, Panima (Champion). 
Antenne scarcely longer than the breadth of the head at vertex; the fourth to 
eleventh joints together about as long as the first three together ; third joint small, 
obeonical, the following joints closely applied to one another, each a little broader 
than its predecessor, so that the tenth is very distinctly transverse. Thorax much 
