Heteromerous Coleoptera from Tierra del Fuego. 333 
H1YDROMEDION, gen. noy. 
Antenne long and slender, the third to tenth joints 
gradually becoming shorter, the tenth being still one-third 
longer than broad. Klytra covering the abdomen, not 
diverging at the apex, the internal margins being con- 
tiguous nearly to the apex. Prosternum sunk between 
the cox, keeled. Mesosternum completely shelving in 
front, compressed between the coxe, which are not much 
separated. Metasternum short, channelled behind; pos- 
terior cox not much separated, 
The rest as in Chitoniseus. 
Hydromedion elongatum, sp. n. 
Elongatum, piceo-testaceum, sat nitidum. Capite sat 
magno, sat crebre subtiliter punctulato. Thorace capite 
paulo latiori, longitudine vix latiori, sat crebre fortius 
punctato, leyiter convexo, antice omnino rotundato, postice 
paulo angustato, angulis posticis [plerumque | fere rectis, 
obtusiusculis. Scutello transverso, basi parce punctulato. 
Elytris basi thorace paulo latioribus, et 2? longioribus, 
postice ampliatis, sat convexis, fortiter punctato-striatis, 
interstitiis sat angustatis, leviter convexis, nitidis; singulo 
elytro ad apicem rotundato. Abdomine subtus parce 
subtilissime punctulato. 
Long. 5 lin.; lat. 2 lin. 
Var.—Head more distinctly punctured. Thorax with 
the sides much rounded, and the posterior angles more 
obtuse. Mesosternum only slightly keeled between the 
cox ; strive of the elytra less closely punctured. 
Hab.—Tierra del Fuego. Brit. Mus. 
PARAHELOPS, gen. nov. 
Eyes prominent. Antenne reaching to the shoulders 
of the elytra: first jomt stout, a little longer than broad ; 
second joint the same length as the first “put less stout; 
third joint as long as the two preceding taken together, 
cylindrical; the fourth scarcely longer than the second ; 
the fifth to tenth gradually becoming shorter, but not 
perceptibly thicker; the eleventh joint nearly globular, 
but with a fine point at the apex. LElytra covering the 
abdomen, the internal margins contiguous, the internal 
angle slightly rounded. Prosternum flat between the 
coxe (which are not very prominent), not produced 
behind. Mesosternum completely shelving in front, the 
