Eirinicaris, Corgosinho, Paulo H. C., Schizas, Nikolaos V., Previattelli, Daniel, Rocha, Carlos E. Falavigna da & Santos-Silva, Edinaldo Nelson dos, 2017

Corgosinho, Paulo H. C., Schizas, Nikolaos V., Previattelli, Daniel, Rocha, Carlos E. Falavigna da & Santos-Silva, Edinaldo Nelson dos, 2017, A new genus of Parastenocarididae (Copepoda, Harpacticoida) from the Tocantins River basin (Goias, Brazil), and a phylogenetic analysis of the Parastenocaridinae, Zoosystematics and Evolution 93 (1), pp. 167-187 : 168

Genus Eirinicaris gen. n.

Diagnosis.

A1 eight-segmented in male, seven-segmented in female. Male A1 haplocer, eight-segmented, haplocer, with small process in segment seven; segments 5, 6, and 7 forming a functional unit for clasping the female, in grasping position, segment 7 bent inwards against segment 6, segment 8 points in opposite direction. Allobasis of Mx with two endites; proximal endite with one seta; distal endite with two elements, one of them transformed into serrated spine; proximal endopodal segment drawn out into claw, distal endopodal segment with two setae. Basis of P1 without remarkable sexual dimorphism; with inner and outer seta, the former longer in male; enp not sexually dimorphic. P2 enp without marked sexual dimorphism. Male P3 with quadratic smooth coxa; basis short, quadratic, with row of spinules close to outer seta, without inner ornamentation; enp modified, aesthetasc-like; exp unisegmented, rectangular, longer than wide, with irregular inner margin and with medial hump, outer margin straight, with unevenly distributed spinules, distal margin flat, inner apophysis shorter than supporting segment, blade-shaped, without distal seta or spine, thumb slightly longer than apophysis, with broad base, proximal expansion on both sides and leaf-shaped distal blade. Female P3 with spiniform enp ⅔ as long as exp-1. Male P4 enp cylindrical, approximately half as long as exp-1, with three distal spinules and one medial outer spinule. Enp of female P4 spiniform, almost as long as exp-1, distally bipinnate. Male and female P5 well developed, a simple triangular plate reaching middle of genital somite in male, inner margin drawn into long and pointed, outwardly curved, spinous process with distal pore, without inner ornamentation, reaching beyond the genital field in female; armature consisting of very long outer basal seta and two additional setae, of which proximal most shorter. Male P6 large, tetra-lobbed fused plate covering genital area. Female P6 represented by naked opercular plate much broader than the height covering genital opening. Male telson with proximal lateral pore, transverse row of small spinules along entire dorsal surface, anterior to sensilla, and rows of spinules covering most of preopercular lateral margin. Female telson smooth, with proximal ventral pore and ventral tube pore near insertion of furca. Male furca irregular, with distal outer pore, longer than width, inner and dorsal margins convex, outer and ventral margins concave; dorsal, inner and outer margins covered by spinules; lateral setae I, II and III, and dorsal setae VII separated by wide gap, setae I, II, and III displaced to antero-ventral position, seta I modified into short spine, with broad base and acuminate tip, seta III 1/3 as long as furca, with one long peduncle and one distal aesthetasc-like structure, 1/2 size of seta II, seta II with broad base, a long peduncle and one distal aesthetasc-like structure; setae IV to VII smooth, dorsal seta (VII) medially inserted in a depression; seta IV inserted subdistally on outer margin, approximately as long as telson without furca, seta V distal, twice as long as seta IV, seta VI distal, 1/2 as long as seta IV; proximal bulges on inner and outer margins. Female furca rectangular with distal ventral pore, longer than wide, smooth, slightly tapering distally, with inner flat lobe; setae smooth, lateral setae I, II, and III, and dorsal seta VII inserted medially and more or less opposite to each other; lateral setae reduced to one small (seta III) and two tiny setae (setae I and II); two uncinate processes anterior to insertion of dorsal seta VII, setae IV, V and VI inserted distally, length and ornamentation of setae IV, V, and VI as for the male; seta VI inserted beneath flat lobe, small spinules close to its insertion.