Mopalia hindsii, copyright Al Kordesch.

Belongs within: Ischnochitonina.

The Mopaliidae are a group of chitons found in the Pacific Ocean and polar regions characterised by a more or less bristly girdle (Smith 1960).

Characters (from Smith 1960): Small to large chitons with tegmentum divided into usual lateral and central areas, sculpture combining radial and longitudinal ribs or lirae that vary in strength from low to high relief. Insertion-plate slits in all valves generally corresponding in position with ends of external ribs, teeth not pectinated. Head valve normally with eight slits but may be smaller or larger by fusion or splitting of one or more teeth, whereas in some forms slits are abnormally multiplied; intermediate and tail valves with single slit on each side, although in one group lacking in tail valve; tail valve with posteromedian sinus; sutural laminae well developed to very large. Girdle more or less hairy or bristly, never with scales, bristles simple or dendritic, in some species growing out of sutural pores, each of which bears one or more hairy bristles.

<==Mopaliidae [Amiculidae, Katharinidae]
    |–Katharina Gray 1847 [=Catharina Dunker 1882, Katherina (l. c.)] S60
    |    `–*K. tunicata (Wood 1815) O27 [=Chiton tunicatus O27; incl. Katherina douglasiae C64]
    |–Amicula Gray 1847 (see below for synonymy) S60
    |    |–*A. vestita (Broderip & Sowerby 1829) [=Chiton vestitus] S60
    |    |–A. amiculata Pallus 1786 [=Chlamydochiton amiculatus] O27
    |    `–A. pallasii (Middendorff 1846) [=Chiton pallasii] O27
    |–Placiphorella Carpenter in Dall 1879 SF77 (see below for synonymy)
    |    |–*P. velata Dall 1879 S60
    |    |–P. atlantica S60
    |    |–P. blainvillii (Broderip 1832) [=Chiton blainvillii] SF77
    |    |–P. borealis Pilsbry 1892 O27
    |    |–P. pacifica Berry 1919 O27
    |    |–P. rufa Berry 1917 O27
    |    `–P. stimpsoni Gould 1859 O27
    `–Mopalia Gray 1847 [=Molpalia Gray 1857; incl. Osteochiton Dall 1886] S60
         |  i. s.: M. acuta Cpr. 1855 [=Chiton acutus] C64
         |         M. blainvillei O27
         |         M. celetoides Dall 1919 O27
         |         M. chacei Berry 1919 O27
         |         M. chloris Dall 1919 O27
         |         M. ciliata (Sowerby 1840) [=Chiton ciliatus] O27
         |           |–M. c. ciliata O27
         |           |–M. c. elevata Pilsbry 1892 [=M. lignosa f. elevata] O27
         |           `–M. c. wosnessenskii Middendorff 1847 O27 [=Chiton wosnessenskii C64]
         |         M. cirrata Berry 1919 O27
         |         M. egretta Berry 1919 O27
         |         M. goniura Dall 1919 O27
         |         M. imporcata Carpenter 1864 O27
         |           |–M. i. imporcata O27
         |           `–M. i. lionotus Pilsbry 1918 O27
         |         M. lowei Pilsbry 1918 O27
         |         M. muscosa Gould 1846 O27 (see below for synonymy)
         |           |–M. m. muscosa O27
         |           |–M. m. acuta Carpenter 1855 O27
         |           |–M. m. kennerlyi Carpenter 1864 O27 [=M. grayii (preoc.) C64]
         |           |–M. m. laevior Pilsbry 1918 O27
         |           |–M. m. lignosa Gould 1846 O27 (see below for synonymy)
         |           |–M. m. porifera Pilsbry 1892 O27
         |           `–M. m. swanii Carpenter 1864 [=M. kennerleyi var. swanii] O27
         |         M. phorminx Berry 1919 O27
         |         M. simpsonii C64
         |         M. sinuata Carpenter 1864 O27
         |         M. stimpsoni (Gould 1859) [=Chiton (Molpalia) stimpsoni] C64
         |–*M. (Mopalia) hindsii (Sowerby in Reeve 1847) S60 [=Chiton hindsii S60, M. muscosa hindsii O27]
         |–M. (Dendrochiton Berry 1911) S60
         |    |–M. (*D.) thamnopora Berry 1911 S60 [=Chaetopleura (D.) thamnopora O27]
         |    |–‘Chaetopleura’ (D.) gothica (Carpenter 1864) O27 [=Ischnochiton (Trachydermon) gothicus C64, O27]
         |    `–‘Dendrochiton’ lirulatus Berry 1963 PP78
         |–M. (Hachijomopalia Taki 1954) S60
         |    `–M. (*H.) integra Taki 1954 S60
         `–M. (Semimopalia Dall 1919) S60
              `–H. (*S.) grisea Dall 1919 S60

Amicula Gray 1847 [incl. Chlamydochiton Dall 1878, Chlamydoconcha Pilsbry 1893 non Dall 1884, Cryptochiton Gray 1847 non Middendorff 1847, Stimpsoniella Carpenter 1873, Symmetrogephyrus Middendorff 1847] S60

Mopalia muscosa Gould 1846 O27 [=Acanthopleura muscosa C64, Chiton (Chaetopleura) muscosus C64; incl. C. armatus C64, C. consimilis Nutt. ms C64, Mopalia consimilis C64, C. ornatus Nutt. 1855 C64]

Mopalia muscosa lignosa Gould 1846 O27 [=Chiton lignosus C64; incl. C. merckii Middendorff 1847 C64, Mopalia merckii C64, C. montereyensis Cpr. 1855 C64, M. montereyensis C64, C. (Chaetopleura) vespertinus C64]

Placiphorella Carpenter in Dall 1879 SF77 [=Placophorella Fischer 1885 S60; incl. Euplacophora Verrill & Smith 1882 S60, Langfordiella Dall 1925 S60, Placophora Dall 1889 nec Agardh 1863 (ICBN) nec Fischer 1885 S60, Placophoropsis Pilsbry 1893 S60]

*Type species of generic name indicated


[C64] Carpenter, P. P. 1864. Supplementary report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Report of the British Association for the Advancement of Science 33: 517–686.

[O27] Oldroyd, I. S. 1927. The Marine Shells of the West Coast of North America vol. 2 pt 3. Stanford University Press: Stanford University (California).

[PP78] Poorman, F. L., & L. H. Poorman. 1978. Additional molluscan records from Bahía de Los Angeles, Baja California Norte. Veliger 20 (4): 369–374.

[S60] Smith, A. G. 1960. Amphineura. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt I. Mollusca 1: Mollusca—General Features, Scaphopoda, Amphineura, Monoplacophora, Gastropoda—General Features, Archaeogastropoda and some (mainly Paleozoic) Caenogastropoda and Opisthobranchia pp. I41–I76. Geological Society of America, and University of Kansas Press.

[SF77] Smith, A. G., & A. J. Ferreira. 1977. Chiton fauna of the Galápagos Islands. Veliger 20 (2): 82–97.

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