Periproctia Stock, 1967

Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), Megataxa 4 (1), pp. 1-6 : 194

Genus Periproctia Stock, 1967

Diagnosis: Prosome comprising cephalosome defined by cephalicshieldandfusedfirsttofourth pedigeroussomites, togetherformingbrood pouch.Pedigerous somitesdefined only by dorsal tergite; fifth pedigerous somite fused to fourth. Free urosome comprising genital and 4 abdominal somites. Anal somite with pair of highly sclerotized, ventral protuberances referred to as “periproctal ring” by Stock (1967) or “perianal ring” by Illg & Dudley (1961). Caudal rami armed with 2 to 4 claws and 2 to 4 setae (total of 6). Antennule 6- to 8-segmented. Antenna 4- segmented; basis with plumose seta representing exopod (rarely absent); compound distal endopodal segment armedwith 9 setae plusterminal claw. Mandible with 5 teeth and 0/1 seta on coxal gnathobase; basis with 1 seta onmedial margin; exopod 2-segmented and armedwith 5 setae (3 on first and 2 on second segment); endopod armed with 2 and 5 or 6 setae on first and second segments, respectively. Maxillule armedwith 5 to 9 setaeon arthrite, 1 on coxal endite (rarely absent), 1 or 2 on epipodite, 2 or 3 on medial margin of basis, 3 on exopod, and 4 on endopod. Maxilla 5-segmented; syncoxawith 3, 1, 2, and 4 setae on first to fourth endites, respectively, 2 setae on basis, and 1, 1, and 2/3 setae on first to third endopodal segments, respectively. Maxilliped unsegmented with 6 to 8 medial plus 1 or 2 apical setae. Legs 1–4 with 3- segmented exopods and 2- or 3-segmented endopods. All legs lacking inner coxal seta. Outer seta on basis very large in leg 1, but small in legs 2–4. Three distal setae on endopod of leg 1 enlarged. First and second exopodal segments of legs 2–4 typically with bifurcate or trifurcate outer distal corners. Third exopodal segments of legs 3 and 4 elongate. Armature formula typically as follows:

	Coxa	Basis	Exopod	Endopod
Leg 10-0	10-0	1-I	I-0/1; I-0/1; II, I, 3/4	0-0; 1, 2, 2/3
Leg 20-0	20-0	1-0	1-1; 1-1; 3, 1, 5	0-0/1; 1, 2, 5
Leg 30-0	30-0	1-0	1-1; 1-0/1; 2, 1, 5	0-0/1; 1, 2, 5
Leg 40-0	40-0	1-0	1-0/1; 1-0/1; 2, 1, 5	0-0/1; 1, 2, 3/4

Leg 5 consisting of protopod with outer seta and free exopodal segment with apical seta.

Type species: Periproctia biuncata Stock, 1967 , by original designation.

Remarks. Stock (1967) considered that the material of Bonnierilla arcuata Brément, 1909 described by Illg & Dudley (1961) was not conspecific with Brément’s species. He designated this material as a new species, P. falsiarcuata Stock, 1967 and placed it in a new genus, Periproctia . This genus takes its name from the modification of the anal somite into the periproctal ring. We agree with this generic placement but we treat P. falsiarcuata as a species inquirendum because was inadequately described and cannot be recognized.