DYTISCIDA. 751 
middle, and one at each side; externally the apex also is obscurely pale. The under 
surface is quite pale, the breast not being at all infuscate. It is rather difficult to 
distinguish the sexes, the male characters being limited to the minute sexual clothing 
of the tarsi; in both sexes the terminal ventral segment is simple, without truncation 
or sinuation. 
The species is also extremely similar to L. suffusus, from which it is distinguished 
by the complete absence of a coxal file. 
19. Laccophilus fragilis. 
Ovalis, angustus, testaceus, elytris sordide testaceis, femoribus quatuor anterioribus palpisque viridescentibus ; 
prothorace basi subtruncato. 
Long. 33, lat. 1? millim. 
Hab. Panama, near the city (Champion). 
An obscure species, of which only two females have been obtained; it belongs to the 
group with elongate prosternal process, and it is probable that the male possesses no 
- coxal file; in the female the middle of the last ventral segment projects as a long lobe 
owing to the segment being truncate-emarginate on each side; there is scarcely any 
sculpture on the ventral segments. It is probable that during life the more pellucid 
parts of the body are viridescent, as some green colour still remains evident on the 
femora, palpi, and antenne. ‘The coloration appears to be the chief point by which 
the species is distinguished from L. ovatus. 
HYDROVATUS (p. 14). 
_ Hydrovatus obscurus (p. 15). 
Before the localities given, insert: —Mexico, Tlacotalpam (Hége). 
1 (4). Hydrovatus concolor. 
Brevissimus, sat convexus, piceo-niger, nitidus ; antennis pedibusque rufis ; crebrius sat fortiter punctatus. 
Long. 23, lat. fere 2 millim. 
Hab. Mexico, near the city (Hége). 
This is a much larger and broader insect than H. obscurus, and is comparatively less 
convex ; it is readily distinguished by the very dark colour and the more numerous 
punctuation. The head is truncate in the middle in front, and the punctuation of the 
thorax is unusually close and distinct. The breast is very deeply and coarsely punc- 
tured. I do not observe any sexual differences among the four specimens obtained. 
Hydrovatus inornatus (p. 15). 
To the Mexican locality given, add :—near the city (Hoge). 
The single example recently received is a male ; it differs strikingly from the female 
