Cylloepus quadratus,

Polizei, Thiago T. S. & Barclay, Maxwell V. L., 2019, The genus Cylloepus Erichson, 1847 (Coleoptera: Elmidae: Elminae) new species and combinations, Zootaxa 4652 (1), pp. 93-100: 94

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Cylloepus quadratus


Cylloepus quadratus  ( Darlington, 1927) comb. n.

Helmis quadrata  Darlington, 1927:95

Diagnosis: Body subparallel. Light brown colour. Surface with micropunctures and short golden setae. Body covered by tomentum (except hypomera and tarsi). Antennae filiform with 11 antennomeres. Frontoclypeal suture distinct, long and straight. Pronotum with sublateral carinae extending from base to anterior margin; disc with a long, wide and deep longitudinal impression, reaching both margins. Elytra with well separated punctures, with 3 carinae; the shorter extending 1/6 of third interval and two sublateral carinae on sixth and eighth intervals, extending 4/5. Abdomen with 5 ventrites, covered by tomentum and punctures well impressed. Legs short, femora and tibiae approximately 1/3 the length of the elytra. Maximum length: 1.96 mm. Maximum width: 0.72 mm.

Type locality: Cienfuegos, Cuba

Material examined: 2 specimens

Holotype: Stone in / rapids / Arimao R. | Soledad Cuba / Cienfuegos / xii-3 1926 / Darlington | Holotype / Helmis  / quadrata / Darlington | Helmis  / quadrata / Darl. | MCZ TYPE / 35202. ( MCZ), (study based on photographs available on the internet in the MCZ type database). Paratype: Stone in / rapids / Arimao R. | Soledad Cuba / Cienfuegos / xii-3 1926 / Darlington | Paratype / Helmis  / quadrata / Darl. | H. / quadrata / Darl. | Cylloepus  / quadrata / Darl. | H.E. Hinton / collection / B.M. 1977-566. | NHMUK 010583874. ( BMNH).

Comments: Cylloepus quadratus  was described from Central America by Darlington (1927) in the genus Elmis  , but was transferred to Cylloepus  by Hinton (1945). Shepard and Megna (2006), in the study of the aquatic Byrrhoidea of Cuba, transferred this species to Hexacylloepus Hinton, 1940  . C. quadratus  has no tomentum on the hypomeron, one of the major diagnostic characters used to differentiate Hexacylloepus  from Cylloepus  (see Hinton 1940a). After the study of the types housed in MCZ and BMNH, we agree with Hinton, this species has all the characters of Cylloepus  ; a robust, elongate body; genae, epipleura, sides of prosternum, mesoventrite, metaventrite, and abdominal ventrites covered by tomentum; pronotum with a sublateral longitudinal carinae on each side and a longitudinal impression, and striate and punctate elytra, without accessory striae; for these reasons, this species is here transferred to the genus Cylloepus Erichson, 1847  .


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Natural History Museum, London