Oreiallagma acutum ( Ris 1918 ) Ris, 1918

Ellenrieder, Natalia Von & Garrison, Rosser W., 2008, Oreiallagma gen. nov. with a redefinition of Cyanallagma Kennedy 1920 and Mesamphiagrion Kennedy 1920, and the description of M. dunklei sp. nov. and M. ecuatoriale sp. nov. from Ecuador (Odonata: Coenagrionidae), Zootaxa 1805, pp. 1-51 : 44-45

publication ID	https://doi.org/ 10.5281/zenodo.182666
DOI	https://doi.org/10.5281/zenodo.5691619
persistent identifier	https://treatment.plazi.org/id/03ED87D9-FF93-BE63-A9D1-A6E6FB30611B
treatment provided by	Plazi
scientific name	Oreiallagma acutum ( Ris 1918 )
status	comb. nov.

Treatment

Oreiallagma acutum ( Ris 1918) View in CoL comb. nov.

Figures 27 View FIGURES 25 – 29 ; 51; 85; 90; 104

Acanthagrion acutum Ris 1918: 120 View in CoL –122, figs. 61–62 [mislabeled as 59] (description of male, illustration of S10 and wings).

Cyanallagma acutum Kennedy 1920: 87 (inclusion in Cyanallagma View in CoL ).

Davies & Tobin 1984: 66 (synonymic list).

De Marmels 1989: 246–247, figs. 1–7 (notes on male and illustrations of head, posterior lobe of prothorax, S7–10, genital ligula, and S10).

Garrison 1991: 11 (synonymic list).

Bridges 1994: VII.3 (synonymic list).

Steinmann 1997: 247 (synonymic list as Cyanallagma acuta ). De Marmels 1997: 138, fig. 82 (key to northern Cyanallagma species, map, comparison with C. thelkterion ). Tsuda 2000: 31 (synonymic list).

Types: Ris (1918) described this species based on nine males (three from Río Zongo, six from Coroico) but did not designate a holotype. We examined a male syntype labeled "Río Zongo, 800 m. / BOLIVIA. [La Paz Dept.] 1913 (2), A.H. Fassl", which also has a red label "Lecto-[in ink by an unknown hand]/Para-/typoid [printed]" affixed to the envelope. De Marmels (1989) stated that he examined two paralectotypes from Coroico. In order to clarify application of the name, we designate the specimen we examined as lectotype (Senckenberg Register No. 10196) that served as basis for our Figures 27 View FIGURES 25 – 29 ; 51; 85; 90. In FNS.

Characterization. Medial lobe of posterior lobe of prothorax slightly constricted at base, subquadrate, with shallow medial concavity on posterior margin ( Fig. 27 View FIGURES 25 – 29 ; as in O. oreas and O. quadricolor ). Distal segment of genital ligula ( Fig. 51 View FIGURES 49 – 53 ) approximately as wide at apex as at base with a pair of latero-apical lobes recurved and directed basally, no accessory latero-medial lobes (unique), and two ental membranous transverse folds (as in O. quadricolor and O. thelkterion ). Dorsal process of male cercus approximately as long as ventral process ( Figs. 85 View FIGURES 85 – 89 ; 90; unique). Dorsum of S1–7 black, of S8–9 blue, sides of S3–7 reddish-orange, of S8 with a black stripe along anterior 2/3, S9 entirely blue and S10 entirely black. Female unknown.

Diagnosis. Species unique by cercus morphology: the long, digit-like dorsal process ( Fig. 85 View FIGURES 85 – 89 ) is shared only with O. thelkterion ( Fig. 86 View FIGURES 85 – 89 ) but is more robust and as long as or longer than ventral process ( Figs. 85 View FIGURES 85 – 89 ; 90); in O. thelkterion , dorsal process is more acuminate and shorter than ventral process ( Fig. 86 View FIGURES 85 – 89 ). In O. prothoracicum ( Figs. 87 View FIGURES 85 – 89 ; 92) and O. quadricolor ( Figs. 88 View FIGURES 85 – 89 a; 93), dorsal process is small and acute, and in O. oreas it is represented by a blunt setose tubercle ( Figs. 89 View FIGURES 85 – 89 ; 94).