RHABDITINAE 3» 



1865, Trans. Linn. Soc. London, xxv, 110; Stiles & Hassall, 

 1905, U.S. Dept. Agric, Bur. Anim. Indust. Bull. 79, 34; de 

 Man, 1910, Zool. Jahrb., Syst., xxix, 362; Goodey, 1922, Ann. 

 Mag. Nat. Hist., (9) x, 297. 



The original diagnosis of this genus given by Ehrenberg 

 (1831) is valueless from the modern standpoint, as is that of the 

 probable genotjqDe, A. fluviatilis (= Vibrio anguillula fluvia- 

 tilis Miiller, 1786). Miiller, 1786, is quoted by Stiles & Hassall 

 (1905) as an earlier author of the name Anguillula. Miiller, 

 however, appears to us, in spite of Stiles & Hassall's statement, 

 to have used this name in 1786 in a specific sense only, in com- 

 bination with Vibrio as genus. Some of the forms included 

 in Vibrio were given trinomial names ( Vibrio anguillula aceti, 

 etc.). Hence the author of the generic name Anguillula is 

 Ehrenberg. As the species fluviatilis and the other species 

 attributed to the genus by Ehrenberg in 1831 are probably 

 unrecognizable, it seems advisable to regard as genotype one 

 of the easily-recognized species A. aceti or A. rediviva {=^ A. 

 glutinis), which were included by the same author later (1838) 

 in the genus. Bastian (1865) designated the species aceti 

 (Miiller) as type of Anguillula Ehrenberg, and this designation 

 does not appear to be invalidated by Stiles & Hassall's argu- 

 ment that A. rediviva (= glutinis) is the type of " Anguillula 

 Miiller." Accordingly, we have made de Man's (1910) 

 diagnosis, based on the species aceti, the chief source of the 

 characters given above. A. rediviva differs only in minor 

 points from A. aceti, so that for practical purposes it is of 

 little importance which is regarded as typical. 



5. Diploscapter Cobb, 1913. 



Cuticle extremely finely striated, without bristles. Lateral 

 alae more or less well developed. Lips four, of which the 

 dorsal and ventral each carries a powerful, outwardly-directed, 

 chitinoid hook-like tooth. Lateral lips larger. Buccal cap- 

 sule prismoid, with uninterrupted wall. Oesophagus with 

 median and posterior swellings, the latter a muscular bulb. 

 Tail in both sexes fairly long, conical, with fine point. Male 

 with caudal alae supported by seven pairs of papillae. Testis 

 single. Vulva slightly behind the middle of the body. Uter- 

 ine branches opposed. Oviparous. Eggs with rough shell. 

 Uterus contains only one egg at a time. 



Hab. About roots of diseased plants ; cosmopolitan but 

 usually tropical. 



Genotype : D. [Rhabditis] coronata (Cobb, 1893). 



Cobb, 1893, Macleay Mem. Vol. Linn. Soc. N.S.W., Sydney, 

 279, 305; 1913, Journ. Washington Acad. Sci., 442; Mico- 

 letzky, 1922, Arch. f. Naturg., Abt. A, Ixxxvii, 266. 



