sperm feeler distinct
Macrostomum tuba Fig 13.jpg
The distal part of the stilette is slightly curved and has an expanded termination which is split in two parts. p. 128
Macrostomum vejdovskyi Fig 15-17.jpg
Macrostomum saifunicum Fig 1-5.jpg
Macrostomum tennesseensis Fig 7-10.jpg
Macrostomum virginianum Fig 18-24.jpg
The penis-stilette is unusually small for an animal of this size. It measures 35micro in length. Morphologically, the stilette is a simple, curved, funnel-like tube with a sub-terminal opening which is subtended by the pointed end. The sperm-cell is spindle-shaped. Two setae are present and there is a very large undulating 'Mittelrippe' on the mid-line of the surface of the cell extending from feeler to 'tail'. Chromatin material is not visible in this sperm-cell. p. 132/133
Macrostomum virginianum Fig 1.jpg
Macrostomum ontarioense Fig 1-5.jpg
sperm-cell composed of feeler, middle part with chromatin granules and two setae and 'tail' region. p. 134
Macrostomum orthostylum Fig 1-6.jpg
Macrostomum ruebushi var kepneri Fig 1-4.jpg
Penisstilette entirely straight, thin walled, terminus sharply pointed, opening terminal. Sperm cells unextended, divided into tail, body, and feeler regions with highly refractive unit in body region, without 'Nebengeisseln'. p. 283