Diopatra brevicirris Grube, 1857: 55.— Grube 1878: 6.
Material examined. None available.
Type locality. Madeira.
Diagnosis. Antennae short, ceratophores 1/2 to 1/3 of total length, lateral antennae to segment 3 (?chaetiger 2), median slightly shorter. Peristomial cirri minute, papilla-like, not longer than 1/3 of ceratophores of palps. Dorsal cirri of parapodia very short, hardly longer than branchial stem thick. Branchiae from chaetiger 4, branchial stem very thick, filaments very short, hardly longer than width of branchial stem, third and fourth pairs longer than body width, almost 12 times as long as dorsal cirrus, last branchia from chaetiger 28.
Remarks. Diopatra brevicirris was described from Madeira on the basis of one incomplete specimen measuring 5 cm in length for 63 chaetigers and 3 mm in width, and remains the only record of this species. The species was characterised by having short antennae, minute peristomial cirri, short dorsal cirri and branchiae with very thick trunks, very short filaments. However, the branchial trunks were described as long, with branchiae 3 and 4 being longer than the width of the body. A later diagnosis (Grube 1857) was slightly different, stating that the branchiae started on chaetiger 3 and consisted of more than 61 pairs, which contradicts the original description, making the later diagnosis unreliable. The brief original description does not fit with the characteristics of any of the species treated here (Table 1) and it is considered as an abnormal or mutilated specimen and declared as a nomen dubium.
Diopatra brevicirris was described in the paper “ Annulata Örstediana ”, following the description of D. rhizophorae Grube, 1857. Whilst the types of D. rhizophorae are held by the Zoological Museum, University of Copenhagen (ZMUC) and have been studied by Paxton (1998), our search for the type specimen of D. brevicirris proved unsuccessful.
Distribution. Single record from Madeira.