482 On Aquatic Carnivorous Coleoptera or Dytiscide. 
The sexes of this species are not easy to distinguish, the differences in the form 
of the tarsi being but small, the male however has the basal joint of the inter- 
mediate feet distinctly broader than it is in the other sex. 
The species is very closely allied to Hydroporus celatus; indeed although its 
elongate form and polished surface render it at first sight very dissimilar from the 
Northern forms thereof, yet from the Pyrenean race it is distinguished, so far as I 
can see, only by its considerably more elongate form. The specimens found, show 
very little variation except that the punctuation of the wing-cases is finer in some 
of them than it is in others. 
Europe. Found by meat an elevation of 6,000 or 7,000 feet, in a small rivulet of very cold clear water, 
in the Grand Valley of Sierra Nevada, Southern Spain. July 17th, 1879. 1151. 
634. Hydroporus regularis, n. sp.—Oblongo-ovalis, sat elongatus, breviter 
tenuius pubescens, sat nitidus, nigricans, antennis pedibusque rufis, illis crassius- 
culis ; prothorace lateribus minus obliquis, medio sublzevi, limbo evidenter punctato ; 
elytris crebre sat fortiter punctatis ; coxis posterioribus parce punctatis; tibiis tar- 
sisque anterioribus latis. Long. 3%, lat. 1§ m.m. 
Variat. colore superno plus minusye dilutiore, aliquando castanescente. 
This species greatly resembles the narrower and more oblong forms of Hydro- 
porus celatus, but it has the thorax differently shaped at the sides, so that a rather 
more considerable angle is formed at the junction with the elytra ; the punctuation 
of the elytra also is closer. The sexes are not easily distinguished. 
Corsica. 392. 
635. Hydroporus obsoletus, Aubé, M.C.—Ovalis, depressiusculus, nitidus, sine 
pubescentia, abdomine pectoreque nigricantibus, supra testaceo-ferrugineus, capite 
thoraceque medio obscurioribus, antennis pedibusque rufis; prothorace medio 
levigato, basi utrinque versus latus depresso, et fortiter punctato ; elytris sparsim 
evidenter punctatis ; coxis posterioribus sparsim obsolete punctatis. Long. 4, lat. 
2 mm. 
I see no sexual characters in this species. The individuals from Spain and 
Portugal, are rather larger, darker in colour, and have the punctuation on the 
elytra finer than those from more northern localities. 
Eurove. (Britain, France, Corsica, Spain, Portugal). 401. 
636. Hydroporus ferrugineus, Steph., M.C.—Oblongo-ovalis, latiusculus, deplan- 
atus, fere sine pubescentia, minus nitidus, abdomine pectoreque nigris, capite 
magno, rufo, prothorace elytrisque ferrugineis, illo lateribus hoc basi signaturisque 
vagis externis dilutioribus; antennis pedibusque rufis, prothorace basi utrinque 
