Belongs within: Monopisthocotylea.
The Capsalidae are monogenean flukes with a double intestine, and male and female pores close together (Dawes 1956).
Characters (Dawes 1956): Oval or elliptical outline, flattened, anterior region constricted to form cephalic lobe. Cuticle non-spinous, or bearing papillae, or having spines dorso-laterally. Prohaptor a pair of suckers, or a pair of glandular areas, or suckers and glandular areas, situated at sides of cephalic lobe. Opisthaptor disk- or sucker-like, sometimes partitioned by septa to form loculi, equipped with one to three pairs of hooks and fourteen marginal hooklets. Mouth ventral, never encircled by an oral sucker, pharynx well developed, caeca with lateral or median diverticula which may be much-branched. One pair of sensory papillae on anterior margin of cephalic lobe, two pairs of eyes. Excretory pore dorso-lateral at or near level of pharynx. Genital pores generally lateral, separate or opening into a common genital atrium. Testes numbering two or more. Ovary in front of testes, median. Vagina present or absent.
<==Capsalidae [Encotyllabidae, Phyllinidae, Tristomatidae, Tristomidae]
|--Nitzschia Baer 1826 [=Nitschia (l. c.), Nitychia (l. c.), Nityschia (l. c.); Nitzschiinae]D56
| |--*N. sturionis (Abildgaard 1794) (see below for synonymy)D56
| |--N. monticellii Price 1939D56
| `--N. superba MacCallum 1921D56
|--Encotyllabe Diesing 1850 (see below for synonymy)D56
| |--*E. nordmanni Diesing 1850 [=Tristoma nordmanni, E. normanni]D56
| |--E. pagelli Beneden & Hesse 1863 [=Tristoma pagelli]D56
| |--E. paronae Monticelli 1907D56
| `--E. vallei Monticelli 1907D56
|--Benedeniinae [Ancyrocotylinae]D56
| |--Pseudobenedenia Johnston 1931D56
| |--Ancyrocotyle Parona & Monticelli 1903D56
| | |--*A. vallei (Parona & Perugia 1895) [=Placunella vallei]D56
| | `--A. bartschi Price 1934D56
| |--Benedenia Diesing 1858D56
| | |--*B. sciaenae (Beneden 1856) (see below for synonymy)D56
| | |--B. melleni [=Epibdella melleni]D56
| | `--B. monticellii (Parona & Perugia 1895) [=Phylline monticellii, Epibdella monticellii]D56
| `--Entobdella Blainville in Lamarck 1818 (see below for synonymy)D56
| |--*E. hippoglossi (Müller 1776) (see below for synonymy)D56
| |--E. diadema (Monticelli 1902) [=Epibdella diadema, Phylline diadema]D56
| |--E. soleae (Beneden & Hesse 1863) [=Phyllonella soleae, Epibdella soleae; incl. E. producta Linstow 1903]D56
| |--‘Epibdella’ squamulaO05
| `--E. steingroeveri (Cohn 1916)D56
|--TrochopodinaeD56
| |--Macrophyllida Johnston 1929D56
| | `--M. antarctica (Kent Hughes 1928)D56
| |--Megalocotyle Folda 1928D56
| | |--*M. marginata Folda 1928D56
| | |--M. hexacantha (Parona & Perugia 1889) [=Placunella hexacanthus, Trochopus hexacanthus]D56
| | |--M. rhombi (Beneden & Hesse 1863) [=Placunella rhombi, Trochopus rhombi]D56
| | |--M. squatinae (MacCallum 1921)D56
| | `--M. zschokkei (Mola 1912) [=Trochopus zschokkei]D56
| `--Trochopus Diesing 1850D56
| |--*T. tubiporus (Diesing 1836) [incl. T. longipes Diesing 1850]D56
| |--T. brauni Mola 1912D56
| |--T. differens Sonsino 1891D56
| |--T. diplacanthus Massa 1903D56
| |--T. gaillimhe Little 1929D56
| |--T. heteracanthus Massa 1903D56
| |--T. lineatus Scott 1901D56
| |--T. micracanthus Massa 1903D56
| |--T. onchacanthus Massa 1906D56
| `--T. pini (Beneden & Hesse 1863)D56
`--Capsalinae [Tristomatinae, Tristominae]D56
|--Capsaloides Price 1936 [=Calsaloides (l. c.)]D56
| |--*C. cornutus (Verill 1875)D56
| |--C. magnaspinosus Price 1939D56
| |--C. perugiai (Setti 1898) [=Tristoma perugiai]D56
| `--C. sinuatus (Goto 1894)D56
|--Tristoma Cuvier 1817D56
| |--*T. coccineum Cuvier 1817 [incl. T. papillosum Diesing 1836, Capsala papillosa]D56
| |--T. integrum Diesing 1850 [incl. T. rotundum Goto 1894]D56
| |--T. levinsenii Monticelli 1891D56
| |--‘*Phylline’ diodontis [incl. Tristomum maculatum Rud. 1819]O05
| `--T. uncinatum Monticelli 1889D56
`--Capsala Bosc 1811 [incl. Tricotyle Guiart 1938 non Manter 1938, Tristomella Guiart 1938]D56
|--*C. martinieri Bosc 1811 (see below for synonymy)D56
|--C. cutanea (Guiart 1938)D56
|--C. grimaldii (Guiart 1938)D56
|--C. interrupta (Monticelli 1891)D56
|--C. onchidiocotyle (Setti 1899)D56
|--C. pelamydis (Taschenberg 1878)D56
`--C. thynni (Guiart 1938)D56
*Benedenia sciaenae (Beneden 1856) [=Epibdella sciaenae, Phylline sciaenae, Tristoma sciaenae; incl. B. elegans Diesing 1858]D56
*Capsala martinieri Bosc 1811 [incl. Tristoma aculeatum, T. cephala Risso 1826, Capsala cephala, Phylline coccinea Schweigger 1820, P. diodontis Oken 1817, Tristoma maculatum Rudolphi 1819, Capsala maculata, T. molae C. sanguinea Blainville 1828]D56
Encotyllabe Diesing 1850 [=Encotylabe (l. c.), Encotyllahe (l. c.); incl. Cheloniella Beneden & Hesse 1863; Encotyllabinae]D56
Entobdella Blainville in Lamarck 1818 [incl. Epibdella Blainville 1828, Ertopdella Rathke 1843, Phylline Oken 1815 non Abildgaard 1790, Phyllonella Beneden & Hesse 1863]D56
*Entobdella hippoglossi (Müller 1776) [=Hirudo hippoglossi, Epibdella hippoglossi, Nitzschia hippoglossi, Phylline hippoglossi, Phyllonella hippoglossi; incl. Capsala elongata Baird 1850, Tristoma hamatum Rathke 1843]D56
*Nitzschia sturionis (Abildgaard 1794) [=Tristoma sturionis; incl. N. elegans Baer 1826, T. elegans, N. elongata, T. elongatum]D56
*Type species of generic name indicated
References
[D56] Dawes, B. 1956. The Trematoda with special reference to British and other European forms 2nd ed. University Press: Cambridge.
[O05] Odhner, T. 1905. Die Trematoden des arktischen Gebietes. In: Römer, F., & F. Schaudinn (eds) Fauna Arctica. Eine Zusammenstellun der arktischen Tierformen, mit besonder Berücksichtigung des Spitzbergen-Gebietes auf Grund der Ergebnisse der Deutschen Expedition in das Nördliche Eismeer im Jahre 1898 vol. 4 pp. 289–372. Gustav Fischer: Jena.