466 F. W. GAMBLE. 



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 Madeira (Langer- 

 hans). It is widely spread over Europe in fresh water. 



Subfamily HYPORHYNCHiNiE. 



"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. Vesicula seminalis and granule- 

 reservoir not distinct. Their contents, however, 

 issue through special chitinous ducts'' (v. GraflF, 

 '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 papillae. The way in which these papillae are 

 used reminds one forcibly of a Monotus (see p. 487). The 

 anterior end, beset with long flagella, is moved actively from 

 side to side as it advances. Short rhabdite» are present over 

 the surface, modified on each side of the body behind the 



