On Aquatic Carnivorous Colcopiern or DytiscidcB. ■■2S:i 



83. Macrovatellus lateralis, n. sp. — Oblongo-ovalis, fere sine pubescentia, opacus, 

 densius punctatus, fuscus, pedibus antenuisque l:jete rufo-testaceis, capite, thoracis 

 lateribus, elytrorumque signaturis marginalibus ferrugineis ; thorace elvtris 

 angustiore, lateribus baud sinuatis,angulis posterioribus fere rectis, fortiter et crebrius 

 sed baud profunde puuctato ; elytris punctatis, scabriusculis; coxis posterioribus for- 

 titer, sed subobsolete punctatis, abdomine obsolete punctate. Long. Gh, lat. 3h in. in. 



The male has the front and middle tarsi broader than the female, the second 

 joint of the front ones being scarcely so long as its greatest width ; the middle 

 trochanters and the basal portion of the femora are set with a ridge of dense yellow 

 pubescence. In the female when the sole of the front tarsus is looked at, it is seen 

 that the length of the third joint is quite twice as great as its breadth. 



South America, (Uruguay). 438. 



84. Macrovatellus rudis, n. sp. — Oblongo-ovalis, fere sine pubescentia, opacus, 

 densius punctatus, piceus, pedibus antennisque obscure rufis, capite ferrugineo, 

 prothorace elytrisque lateribus vage et obsolete ferrugineo-signatis ; thorace elytris 

 multo angustiore, lateribus haud sinuatis, angulis posterioribus fere rectis, fortiter 

 et crebrius sed baud profunde punctato ; elytris dense punctatis, scabriusculis ; coxis 

 posterioribus fortiter, sed subobsolete punctatis ; abdomine obsolete punctato. 

 Long. 62, lat. 3h m.m. 



This species is distinguished from Macrovatellus lateralis only by the rather more 

 obscure colour, slightly broader elytra, and by the joints of the front and middle 

 tarsi being just a little broader in proportion to their length : the distinctions 

 between their structure in the two sexes being the same as in M. lateralis. 



South America. 439. 



85. Macrovatellus sahlbergi, n. sp. — 6 Oblongo-ovalis, fere sine pubescentia, dense 

 fortiter profundeque punctatus, piceus, capite antennisque minus diUite ferrugineis, 

 elytris ad latera signaturis minus distinctis rufescentibus ; prothorace fortiter 

 transverse, pone medium leviter angustato, ante basin evidenter transversim dej^resso, 

 lateribus obsolete explanatis, opaco, crebre punctato ; elytris subnitidis, dense fortiter 

 profundeque punctatis ; coxis jiosterioribus ruguloso-punctatis, abdomine indistincte 

 punctato. Long. 62, lat. 3f m. 



In the male the front and middle tarsi are moderately broad, the third joint 

 however being of the same width as the basal joint; the trochanters and the basal 

 portion of the femora of the middle legs bear a ridge of dense yellow pubescence. 

 The species resembles M. rudis greatly, but is readily distinguished by its broader 

 and more transverse thorax, and the more shining, and more coarsely and distinctly 

 punctured elytra. I have seen two males. 



South America. Found at Petropolis iii March, 1850, by Dr. F. Sahlberg, and sent me by his son, 

 Dr. J. Sahlberg. 440. 



TRANS. BOY. DUB. SOC, M.S., VOI.. II. 2 I" 



