On Aquatic Carnivorous Coleoptera or Dytiscide. 287 
TI. 14.—Genus LACCOPAILUS. 
Prosternal process with unispinose extremity ; spurs of hind tibize emarginate at 
their apex. Head very short. 
The species* forming this aggregate are numerous and of extreme difficulty to 
study and discriminate. The most useful and natural method of arrangement I can 
suggest at present is one based on the length of the prosternal process, and on the 
presence or absence of a coxal file ; and in order to further facilitate reference I have 
combined with this arrangement the fact whether the species are found in the 
New or in the Old World. The species seem to inhabit more especially the warmer 
parts of the world, and as I feel sure that not one-fourth of those existing are 
known to us, I do not think it worth while at present to try and effect a more 
detailed or truly natural classification of the species of the aggregate. The coxal file 
when present consists of a series of very fine ridges, placed on a segment of a circle, 
commencing near the middle of the body just where the coxal lines start from the 
extremity of the metasternum, and from this point they extend outwards and 
backwards so as to form a curved series of parallel furrows. The prosternal process 
has the extremity very slender, so that in the species where it is elongate it is not 
unfrequently broken off, but even in such a case its length can be estimated by that 
of the groove for its reception on the anterior portion of the metasternum. 
* In addition to those enumerated in the text, the following also belong to the genus :-— 
Hydroporus inefficiens, Walk. (No. 1,382 huj. op.) ; Ceylon. 
Laccophilus adspersus, Boh. (No. 1,474) ; Caffraria. 
Laccophilus baeri, Regt. (No. 1,475); Manilla. 
Laceophilus cayennensis, Aubé (No. 1,476) ; South America. 
Laccophilus decoratus, Boh. (No 1,477) ; Manilla. 
Laccophilus flavescens, Motsch. (No. 1,478) ; Ceylon. 
Laccophilus hydaticoides, Regt. (No. 1,479) ; Manilla. 
Laccophilus lineatus, Aubé (No. 1,480) ; Mauritius. 
Laccophilus mexicanus, Aubé (No. 1,481), 4 near No. 100; Mexico. 
Laccophilus orientalis, Aubé (No. 1,482), ?near No. 161; Java. 
Laccophilus ornatus, Aubé (No. 1,483), ? near No. 118; South America. 
Laccophilus peecilus, Klug (No. 1,484) ; Egypt. 
Laccophilus proteus, Regt. (No. 1,485); Manilla. 
Laccophilus pumilio, Lec. (No 1,486) ; North America. 
Laccophilus quadrisignatus, Aubé (No. 1,487) ; South America. 
Laccophilus rivulosus, Klug (No. 1,488), ? near No. 148; Madagascar. 
Laccophilus streehmi, Th. (No. 1,489), ? No. 128 var. ; Finland. 
Laccophilus transversalis, Regt. (No. 1,490); Manilla. 
Laccophilus transyersus, Motsch. (No. 1,491); Burmah. 
Laccophilus umbrinus, Motsch. (No. 1,492); Egypt. 
Laccophilus uniformis, Motsch. (No. 1,493) ; India. 
Laccophilus vermiculosus, Gerst. (No. 1,494); East Africa. 
Laccophilus yvicte, Le Guill. (No. 1,495 ; Chili. 
