Chasmogenus Review of the genus Chasmogenus Sharp, 1882 of northeastern South America with an emphasis on Venezuela, Suriname, and Guyana (Coleoptera, Hydrophilidae, Acidocerinae) Smith, Rachel R. Short, Andrew Edward Z. ZooKeys 2020 934 25 79 8VW66 2045C95A-D4F1-5109-8C93-8217F213E5CA sp. C Insecta Hydrophilidae Chasmogenus CoL Animalia Chasmogenus Coleoptera 0 25 Arthropoda genus   Chasmogenussp. C Short, Salisbury, & La Cruz 2018: 193.  Material examined (4).  Guyana: Region 6: Upper Berbice, Basecamp 2, 4°45.301'N, 58°00.404'W, 49 m, 26.ix.2014, leg. Short, Salisbury and La Cruz, shallow detrital pools in forest draining into creek, GY14-0926-01A (4 females, CBDG, SEMC including DNA Voucher SLE1783).  Remarks. This species is only known from four female specimens. We sequenced one specimen which was genetically distinct from all other described species in the region and likely represents an undescribed species. However, because the aedeagus is critical for identification, we have chosen not to formally describe this species until males can be found. This species is morphologically similar to  C. pandus, particularly the reddish dorsal coloration and smaller size. It was first recognized as a distinct morphospecies by Short et al. (2018), where it was listed as "  Chasmogenussp. C", and we have followed this naming convention for continuity.