Bock S 1923 (citation)- Karling TG 1940 (citation)- makes this a separate Sub Order under Order Archoophora. p 230 (=Hofsteniidae Bock 1923; Hemacoela Steinbock 1924). Definition: "Archoophora with gut and muscular pharynx simplex (tubiformis). Nervous system epithelial with weakly developed brain. Statocyst with 1 lethosphere. Ducts not found. A single ventral genital pore. Female ducts lacking or opening near the male apparatus into a common atrium. Without female accessory organs. Marine." also p 223, 225, 227, 228. Westblad E 1948 (citation)- p 60 lists this as separate Sub Order under Archoophora according to Karling- he agrees and so places it. p 63 close to aceols (no 2 next to Acoels no 1), p 65 definition. "Archoophora with digestive endocytium and muscular pharynx simplex opening at anterior end. Frontal glands present. Basal membrane O. Nervous system mostly epithelial. Statocysts present. Protonephridia O. Male genital opening ventral in anterior part of bady. Female and male ducts O. Female accessory apparatus O. Marine. A single genus Hofstenia under his Order Archooplines.[Bush translation] Hyman LH 1951 (citation)- vol 2, p 150 includes Hofstenia in Lecithoepitheliata. Papi F 1957 (citation)- places this family in the Acoela on the basis of his study of the anatomy of Hofsteniola pardi which he describes in detailp See diagnosis of Sub Order and genera p 145. Note that Hyman in the Invertebrates vol II places it in the Alloeocoela under the Lecithoepitheliata, also Meixner had a Family Proporoplanidae which included this [Bush: or did it? Probably not- Proporoplana is a different species - see under Prolecithophora Karling 1940]. p 145 "Diproporida- Abursalia Acoela with nervous in whole or in part superficial. Mouth subterminal and ventral close to anterior end. Pharynx simplex very long, sometimes in an atypical position and complicated by muscle layers. Digestive parenchyma follow. Penis with cuticular armature, female antrum tube-shaped, male genital pore a little behind the mouth. Female reproductive system consists only of eggs, ferilized by dermal inpregnation or by hypodermal injection." Genus Hofstenia and Hofsteniola. Marcus EDB-R 1957 (citation)- p 173 notes she agrees with Karling TG 1940 (citation) and Westblad E 1948 (citation) in placing this family in the Archoophora [note Meixner 1938 (citation) places these in the Acoela] Hyman LH 1959 (citation)- p 734-5 on rank and position of this- might be a family under Acoela. Beauchamp P de 1961 (citation)- makes this a separate Sub Order . Karling TG 1968 (citation)- notes this family is transferred here from the Lecithoepitheliata by Papi F 1957 (citation). Dorjes J 1968 (citation)- Lists synonyms p 103-4: Family Hofsteniidqae, Bock 1923 Section Hemacoela, Steinbock 1924 Family Hofsteniidae, Bresslau 1933 Family Hofsteniidae, Meixner 1938 Sub Order Hofsteniidae, Karling 1940 Sub Order Hofsteniidae, Westblad 1948 Family Hofsteniidae, Hyman 1951 Family Hofsteniidae, Steinbock 1966 p 104 definition- "Acoels with epithelial nervous system or long nerves lying within the outer muscle layers. Mouth opening ventral near the anterior end or terminal. Pharynx very long and tube shaped with simple or strong musculature or bell shaped. Testes diffuse. Seminal vesicle may be lacking. Granular vesicle with penis, the lattere out of cuticularized needle stylets. Male reproductive opening directly behind mouth opening, widening into a male antrum. Ovaries ventral, either paired or follicular. Female accessory organs lacking." key- 1. Nervous system einsuncken. Pharynx bell shaped--------------------Marcusiola 1. Nervous system epithelial- Pharynx long tube like---------------------------2 2. Mouth opening ventral. Seminal vesicle lacking--------------------Hofsteniola 2. Mouth opening subterminal. Seminal vesicle present----------------Hofstenia Karling TG 1970 (citation)- places them in the Acoela. Crezee M 1975 (citation)- p 840-1 on pharynx types.
translated from Steinbock (1966) [7217]
key to species of Hofstenia
1. Mouth opening ventral, pharynx a long tube with simple musculature
. . . . . . . . . . . . . . . . . . . . . . . . . . . . Hofsteniola
Hofsteniola Papi 1957. With epidermal nerve plexus, mouth opening
ventral, pharynx long, tubiform, weak-muscled. No seminal vesicle
(false seminal vesicle), no ovary follicles, yolk cells
phagocytose. Single species H. pardii Papi
2. Mouth opening almost terminal, pharynx long, extraordinarily
strongly muscled . . . . . . . . . . . . . . . . . . . . . Hofstenia
Hofstenia Bock 1923. With epidermal nerve plexus, mouth opening
almost terminal, pharynx extraordinarily muscular, with seminal
vesicle, with ovary follicles. 4 species
Key (with better knowledge of species H. miamia and H. beltagii it
would be possible to develop a better key)
1. Male genital canal (antrum masculinium autorum) essentially
longer than the penis sac; large, 5-9 mm forms . . . . . . . . . 3
2. Male genital canal and penis sac roughly of equal length, penis
stylet consists of about 50 needles . . . . . . . H. miamia Correa
Beginning part of the male genital canal widened in a ball
shape, end portion positioned perpendicular to ventral surface
. . . . . . . . . . H. beltagii Steinbock
3. The tip/point of the penis bulb projects only a little into
the male genital canal, penis sac shallow . . H. atroviridis Bock
penis bulb surrounds a long "penis ball", penis stylet of about
10 needles . . . . H. giselae Steinbock
4. Mouth opening almost terminal, pharynx short, bell-shaped
. . . . . . . . Marcusiola
Marcusiola. Pharynx bell shaped, nervous sytsem orthogonal,
ventral longitudinal nerves inside the body-wall musculature.
The genus is still not completely known. Single species
Marcusiola tinga (du Bois-Reymond-Marcus)
Return to Prosopharyngida Hofsteniidae