Simplicaris, Galassi & Laurentiis, 2004

Galassi, Diana M. P. & Laurentiis, Paola De, 2004, Towards a revision of the genus Parastenocaris Kessler, 1913: establishment of Simplicaris gen. nov. from groundwaters in central Italy and review of the P. brevipes-group (Copepoda, Harpacticoida, Parastenocarididae), Zoological Journal of the Linnean Society 140 (3), pp. 417-436 : 418-419

SIMPLICARIS GEN. NOV.

Diagnosis. Parastenocarididae . Body vermiform, without clear demarcation between prosome and urosome; integument without surface pits, very feeble sclerotization. Hyaline frills of cephalothorax and somites bearing P2–P4 and abdominal somites plain. Female genital and first abdominal somites completely fused forming a genital double-somite. Anal operculum smooth. Caudal ramus cylindrical, elongate; with seven setae in both sexes. Sexual dimorphism in body size, antennule, P3, P4 endopods and ornamentation of basis, and genital segmentation.

Rostrum small, not defined at base. Antennule 7- segmented in female, with aesthetasc on segments 4 and 7; 8-segmented and haplocer in male, with geniculation between segments 6 and 7, and aesthetasc on segments 5 and 8. Antenna with allobasis; free distal endopodal segment with two lateral and five distal elements, two of them geniculate, the outermost distally crenulate. Antennary exopod well defined at base, bearing one seta. Mandibular palp 1-segmented, with two apical setae. Maxillule: praecoxal arthrite with three curved robust spines plus four anterior subterminal setae; one element inserted on an apparent peduncle (or pedestal segment); one element on coxal endite; basis with three naked setae, endopod and exopod absent. Maxilla: maxillary syncoxa with two endites, proximal one not defined at base, bearing one seta, distal endite well developed, with two apical elements, one of which apically crenulate, and subapical element; allobasis drawn out into a crenulate claw; endopod incorporated into allobasis or rudimentary, with two setae. Maxilliped well developed, subchelate; syncoxa unarmed, basis elongate, endopod represented by claw, with one accessory seta.

P1, P2 and P4 with 3-segmented exopods in both male and female; exp-1 distinctly longer than segments 2 or 3, or as long as exp-2 and -3 combined. P1 basis without inner seta in both sexes; P2 and P4 basis without outer seta. P1: exp-1 with outer spine, exp-2 unarmed, exp-3 with two outer spines and two apical geniculate setae. Endopod 2-segmented; enp-1 unarmed, enp-2 with one apical geniculate seta and one spine. P2: exp-1 as long as exp- 2 and -3 combined, with one outer spine; exp-2 unarmed, exp-3 with one outer spine and two apical setae; endopod 1- segmented. Female P3 with two-segmented exopod and 1-segmented endopod. Male P3 transformed, basis with or without rudimentary endopod; when present, endopod reduced to a simple and short seta; basal outer seta well developed, exopod slender in which former segments 1 and 2 are fused, former proximal segment representing largest part of leg; former distal segment represented by a short part extended from the insertion of outer spine to the subterminal constriction, ending with rounded apophysis, outer subdistal spine representing outer spine of former proximal exopodal segment, not longer than apophysis. P4: exp-1 with one outer spine, exp-2 unarmed, exp-3 with one outer spine and one apical seta. Female endopod 1-segmented, male endopod transformed, ornamentation of basis consisting of two elements, located anterior to insertion of endopod. P5 absent in both sexes. P6 absent in the male; reduced in the female to form small genital operculum without any trace of armature.