BRITISH MARINE TURBELLARIA. 209 



25. Gyrator hermaphroditus, Ehrbg. (10). 



1875. Pbostoma lineaee, Mcintosh (45). 

 1879. „ „ Hallez (50). 



Details of Mcintosh's specimens are not given. I append the 

 following observations which I have made on specimens taken in the 

 neighbourhood of Manchester. 



Length 1 mm. Body in the highest degree contractile, colourless, 

 cylindrical, tapering anteriorly. Proboscis very mobile. Brain, eyes, 

 and pharynx as in Macrorhynchus. 



The genital organs are distinguished by the presence of a poison- 

 dart appended to the copulatory organ. Hallez has given a full 

 account of this with figures (see 43, pis. xx — xxii). The use of this 

 stylet as an offensive weapon has been seen by Schmidt (' Denkschr. 

 math.-nat. Klasse,' Wien, 1857) and Hallez ('Arch. Zool. Expt.,' 1873). 

 The animal bends the hinder end of its body towards the ventral 

 surface when close to its prey (small Entomostraca), which it stabs 

 repeatedly with its poison-dart. 



Habitat. — In sea water this form is only known from St. Andrews 

 under stones (Mcintosh) and Maderia (Langerhans). It is widely 

 spread over Europe in fresh water. 



Subfamily HyporhynchiNjE. 



" Proboscis small, behind the anterior end, its sheath opening on the 

 ventral surface. Muscular cone present. Numerous short muscular 

 fibres constitute retractors. Spermotheca with chitinous appendage. 

 Vesicida seminalis and granule-reservoir not distinct. Their con- 

 tents, however, issue through special chitinous ducts " (v. Graff, 

 ' Monogr.,' p. 336). 



Genus 15. — Hyporhynchus, v. Graff. 



26. Hyporhynchus armatus (Jensen). 



Length 1 — 1-5 mm. Body elongate, cylindrical, truncate at both 

 ends, white. Hinder end provided with strong adhesive papilloe. The 

 way in which these papillse are used reminds one forcibly of a Monotus 

 (see p. 227). The anterior end, beset with long flagella, is moved 

 actively from side to side as it advances. Short rhabdites are present 

 o 



