ON THE ANGUILLULID/E. 125 



Male, longer than female, but narrower; length ^^'j hreadth ■^\^" . 



Anns 5-5^5" from posterior extremity, which is altogether narrower than in the female. 

 Spicules not distinctly visible, slightly curved, tAo" long. Accessory piece more dis- 

 tinct, straight, airoo" long- 



Sab. Between the sheaths of leaves of wheat-stalks, from stubble-fields, Broadmoor, 

 Berks. 

 2. C. STRiATTJS, n. sp. (Plate X. figs. 107, 108.) 



Female, length xs") breadth yy^". 



External Characters. — Body white, tapering anteriorly and posteriorly ; posterior ex- 

 tremity proportionally narrower than in last species. Head bilobed. Strise transverse, 

 very distinct, xirooo" apart. 



(Esophagus \i]i of total length. Intestine sparingly covered with light-coloured he- 

 patic particles. Amis 3-^" from posterior extremity. Vulva slightly anterior to pos- 

 terior third of body. Excretory duct readily visible, -^' from anterior extremity. 



Male, not seen. 



Sab. Sandy soil, about rootlets of wheat, Broadmoor, Berks. 



12. TYLENCnUS \ Bastian. 

 ' Vibrio, Miiller; Anguilhda, Hemprich & Ehrenberg; R/iaMitis, Dujardin. 

 Gen. Char. Body tapering at extremities. Caudal sucker, none. Integument having 

 distinct transverse striae ; no setoj or papillre. Pharynx modified into an exsertile 

 spear, with a trilobed base. (Esophagus having a roiinded muscular swelling about 

 its middle ; canal thread-like, continuous Avith spear, most distinct in anterior half. 

 Intestine rather indistinct, sjiaringly covered with coarse, colourless fat-granules; 

 intestinal tube proper easily recognizable. Vulva considerably posterior to middle 

 of body. Uterus unsymmetrical ; traces of abortive posterior median segment. Spi- 

 cules rather stout, generally united to the posterior accessory p)iece. Caudal aim 

 in males membranous and unsupported by rays. Euct of excretory ventral gland 

 linear, rigid, and curved at termination. Lateral vessels distinct, occasionally 

 flexuous ; terminations uncertain. 

 Movements sluggish. 



The tenacity of life possessed by the members of this genus, as well as those of Plectus, 

 Aphelenchus, and Cephalobus, is a most remarkable peculiarity, which may perhaps, in 

 some slight degree, be accounted for by the structure of the integument, which seems 

 calculated to enable them to resist actual desiccation and the evaporation of the 

 natural moisture from their tissues for a much longer period than could be the case 

 with other species, whose tegumentary organs are constructed upon a different principle. 

 I have demonstrated by actual microscopical observation the presence of a plurality of 

 integumental pores in the species of many genera ; and all these animals (as well as many 

 others, in which such pores have not been recognised, owing to the smallness of^heir 

 size and the intrinsic difficulty of the investigation), when immersed in a dense medium, 



' TvXos, a hwb, and ey^os, a spear. 



