ON THE ANGUILLULIDÆ. 125 
Male, longer than female, but narrower; length 3”, breadth 535". 
Anus 515 from posterior extremity, which is altogether narrower than in the female. 
‘cules not distinctly visible, slightly curved, 44,5" long. Accessory piece more dis- 
tinct, straight, 3000 long. 
Hab. Between the sheaths of leaves of wheat-stalks, from stubble-fields, Broadmoor, 
Berks. 
9, C. STRIATUS, n. sp. (Plate X. figs. 107, 108.) 
Female, length 25", breadth yiz- 
External Characters.—Body white, tapering anteriorly and posteriorly ; posterior ex- 
tremity proportionally narrower than in last species. Head bilobed. Strive transverse, 
very distinct, 55000 apart. 
Esophagus ith of total length. Intestine sparingly covered with light-coloured he- 
patic particles. Anus 555 from posterior extremity. Vulva slightly anterior to pos- 
terior third of body. Æxcretory duct readily visible, 375" from anterior extremity. 
Male, not seen. 
Hab. Sandy soil, about rootlets of wheat, Broadmoor, Berks. 
19. TYLENCHUS !, Bastian. 
Vibrio, Müller; Anguillula, Hemprich & Ehrenberg ; Rhabditis, Dujardin. 
Gen. CHAR. Body tapering at extremities. Caudal sucker, none. Integument having 
distinct transverse striæ ; no setæ or papille. Pharynx modified into an exsertile 
spear, with a trilobed base. (Esophagus having a rounded muscular swelling about 
its middle; canal thread-like, continuous with spear, most distinct in anterior half. 
Intestine vather indistinct, sparingly 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 piece. Caudal ale 
in males membranous and unsupported by rays. Duct 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 
mtegumental pores in the species of many genera; and all these animals (as well as many 
others, in which such pores have not been recognized, owing to the smallness of their 
Se and the intrinsic difficulty of the investigation), when immersed in a dense medium, 
1 dos, a knob, and ëyyos, a spear. 
