Diagnosis of P. tricarinata Riseman et al. 2001

(Fig. 22)

Holotype. Male holotype, deposited at Museu de Zoologia da Universidade de São Paulo (MZSP) cat. no. 12820.

Type locality. Ubatuba, northern São Paulo State, Brazil, 23°38'S, 44°49'W, 48 m, 22 January 1986.

Paratypes. Series of specimens from Ubatuba, São Paulo State, Brazil — MZSP # 12821: 23°50'S, 45°10'W, 27 October 1985, 38–40 m; 2 males, 9 females, 7 juveniles. MZSP # 12822: 23°34'S, 45°06'W, 9 July 1986, 25 m; 1 male, 1 female, 1 juvenile. USNM # 288407: 23°39'S, 44°53'W, 20 April 1986, 45–48 m; 2 males, 2 females, 3 juveniles. USNM # 288408: Ubatumirim, São Paulo State, Brazil, 23°22.50'S, 44°53'W, May 1993, 15 m; 1 female .

Diagnosis. Body long, cylindrical, length 4.5–5.75Ⅹ width, with pereonal segments loosely articulated. Adult length to at least 10.5 mm. Pereon loosely articulating with and overlapping pleon. Cephalon with transverse cuticular ridge between frontal ridge and interocular furrow. Antennae extended to middle of first pereonite. Frontal lamina narrow, usually spatulate (expanded anteriorly); visible in dorsal aspect projecting between antennular peduncles. Pereonite 7 longest. Pleotelson posterior margin narrow, slightly subacute; with several plumose marginal setae and 4–6 small robust setae. Pereopods 1–3 with ischium and merus superior distal angles greatly produced, with meral lobe reaching midpoint of propodus; inferior margin of merus and carpus with long acute robust setae. Pereopods 4–7 posterior distal margin of ischium with studded-biserrate setae. Pereopod 7 superior distal angle of merus with long slender plumose setae. Pleopod 2 appendix masculina broad and straight, of relatively constant width until apex where it narrows to a point. Uropod with cluster of very long simple setae at apices of both endopod and exopod; endopod distal margin broad and truncate; exopod shorter than or just reaching endopod notch.

Distribution. Politolana tricarinata is known from the type locality and from the São Sebastião coast, south of Ubatuba, Brazil. Specimens were collected only on the inner shelf, from 15 m to 48 m depth, on sandy bottoms where medium and fine grains predominate, in water temperatures of 16°C–22°C. Politolana eximia is also found within the warm-temperate waters of the Brazilian coast but at depths greater than 50 m.