Chthamalus, Ranzani, 1817

Benny K. K. Chan, H. - N. Chen, P. R. Dando, A. J. Southward & E. C. Southward, 2016, Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia), PLoS ONE 11 (3), pp. 1-51 : 41-42

Key for identification of Chthamalus species in the North-Eastern Pacific.

1a) Tergum with deep longitudinal furrow on outer surface, anterior ramus of cirrus III approximately 1.5 x the length of the posterior ramus............. Chthamalus panamensis

1b) Tergum without deep longitudinal furrow on outer surface, both ramii of cirrus III of equal length......................................................................... (2)

2a) Left and right scuta and terga strongly asymmetrical, tergoscutal tissue flaps white......................................................... Chthamalus anisopoma

2b) Left and right scuta and terga symmetrical or only slightly asymmetrical, tergoscutal tissue flaps not white.................................................................. (3)

3a) Cirrus II, with bidenticulate setae without basal guards on the distalmost segment. Chthamalus dalli

3b) Cirrus II, with bidenticulate setae with basal guards on the distalmost segment....... (4) 4a) Labrum with small, almost invisible, teeth....................... Chthamalus hedgecocki

4b) Labrum with up to 10 teeth on either side of cutting margin......................... (5)

5a) Bidenticulate setae with basal guards on the 3 distalmost segments of the posterior ramus of cirrus II............................................. Chthamalus newmani sp. nov.

5b) bidenticulate setae with basal guards on less than 3 of the distalmost segments of the posterior ramus of cirrus II........................................................... (6)

6a) Tergoscutal flaps dark brown in life, bidenticulate setae with basal guards on the distalmost segment of the posterior ramus of cirrus II............................ Chthamalus fissus

6b) Tergoscutal flaps orange in life, bidenticulate setae with basal guards on the 2 distalmost segments of the posterior ramus of cirrus II................. Chthamalus alani nom. nov.