MADEIRAN COLEOPTERA. 31 
Genus 34. LACCOBIUS. 
Erichson, Kat. der Mark Brand. i. 202 (1837). 
86. Laccobius minutus. 
Chrysomela minuta, Linn., Fina Suec. 166 (1761). 
Hydrophilus bipunctatus, Fab., Syst. Eleu. 1. 254 (1801). 
Laccobius minutus, Erich., Kaf. der Mark Brand. i. 203 (1837). 
, Woll., Ins. Mad. 95 (1854). 
Inhabits the smaller streams of Madeira and Porto Santo, being 
confined principally to the higher altitudes,—the specimens from the 
latter island (where I first detected it in 1855) being rather larger 
and paler than those from the former. Rare. It occurs also in the 
Canarian Group. 


Genus 35. HYDROBIUS. 
Leach, Zool. Miscell. iii. 93 (1817). 
87. Hydrobius Marchantiz, n. sp. 
H. subglobosus niger, antice nitidus et sat distincte punctulatus, 
postice subopacus et levius punctulatus, prothoracis lateribus 
diluto-testaceis, elytris punctulis minutissimis superinjectis ubique 
(sed preesertim apicem versus) confertissime obsitis, singulo stria 
suturali postica leviter impresso, ad apicem plus minus dilutioribus, 
pedibus rufo-piceis. 
Long. corp. lin. 14-1}. 
H. subglobose, but rather acuminated at its apex, black, shining and 
distinctly punctured anteriorly, but more opake and less evidently 
punctured posteriorly,—the punctures being denser and coarser on 
the head than on the prothorax, and on the prothorax than on the 
elytra. Prothorax with the sides, and its extreme anterior margin, 
more or less diluted-testaceous. Hlytra with a very lightly-im- 
pressed sutural line on each, behind ; and (in addition to the other 
punctures) closely beset with an under-sculpture of most delicately 
impressed points (perceptible only beneath the microscope),— 
these minute punctules, however, becoming gradually more evident 
as we approach the apex {—a peculiarity which at once accounts 
for the greater opacity of the surface in that particular region]; the 
apex more or less obscurely diluted-testaceous (sometimes entirely 
concolorous with the rest of the surface). Wings obsolete. Palpi 
and antenne testaceous,—the club of the latter being darker (and 
very obtuse and abrupt). Legs rufo-piceous. 
The comparatively large size of the present Hydrobius will, apart 
from other differences, at once distinguish it from its Madeiran ally, 
the H. conglobatus ; whilst the approximation which it displays to 
the peculiarity of sculpture which obtains in that insect, in conjune- 
