Chevrolat 1863: 207 Knisch 1920: 56 Hydrochus tarsalis Chevrolat Hydrochus tarsalis Chevr. Det.J.L.Hellman Hydrochus tarsalis Chevrolat Type designations for Neotropical water beetles in the genus Hydrochus Leach 1817 (Coleoptera: Hydrochidae) Perkins, Philip D. Zootaxa 2019 2019-11-27 4701 2 149 167 3N6CM Chevrolat Chevrolat [151,513,1561,1588] Insecta Hydrochidae Hydrochus Animalia Coleoptera 11 160 Arthropoda species tarsalis   Figs. 10, 13D     Hydrochus tarsalis  Chevrolat 1863: 207.    Hydrochus metallipes  Knisch 1920: 56; new synonymy.   Hydrochus tarsalis Chevrolatwas described based on a single specimen from Cuba(“ Cuba. D. F. Poëy. Unique– collection de l’auteur”). In2019, Antoine Mantilleri(MNHN), very kindly did a comprehensive search for the type specimen in the Chevrolatand Bedelcollections, and was unable to find it. Toestablish taxonomic stability regarding this species, a specimen from Cuba, collected by P. J. Darlington, is selected to serve as  neotype, and has been labeled such. Thisspecimen is deposited in the MCZ collection. Thehabitus, male genitalia and pin labels of this specimen have been imaged ( Figs. 10, 13D). Neotypelabels ( Fig. 13D): “Soledad, Cuba( Cienfuegos)  June 1929Darlington // Hydrochus tarsalis Chevr. Det.J.L.Hellman// HABITUS/GENIT. DIGITAL IMAGES captured 2019 P.D. Perkins// [red] NEOTYPE  Hydrochus tarsalisChevrolatdesig. P. D. Perkins.”   Remarks.  Hydrochus tarsalisis a large species. Chevrolat (1863)gives the size of the unique type as “long. 4 ½ mill., lat. 1 3/4 mill.” There is only one currently known species of  Hydrochusin Cubathat is this large. The external characters, and the male genitalia, of the lectotypeof  H. metallipesKnischdo not differ significantly from those of the neotypeof  H. tarsalis.  Hydrochus metallipesis therefore hereby placed as a junior synonym. 2460219436 [376,486,1766,1792] 1929-06 MNHN, MCZ D. F. Poey. Unique & P. J. Darlington & P. D. Perkins & P. D. Perkins. Cuba In Chevrolat Antoine Mantilleri 11 160 3 Cienfuegos neotype