92 ASCAROIDEA 



j. Trilepta Cobb, 1920. 



Cuticle unstriated, without bristles except anteriorly. Head 

 slightly expanded, with two crowns of bristles, the posterior 

 long and apparently jointed. Lateral organs short transverse 

 slits. Pharynx wide, almost cylindrical, perhaps containing 

 a single tooth at its anterior end. Oesophagus cylindroid, 

 without bulb. Caudal end of male without supplementary 

 organs. Spicules slender. An inconspicuous accessory piece 

 present. Testis single, anterior, outstretched. Female unde- 

 scribed. Caudal glands and spinneret apparently absent. 



Hab Marine (in sand). 

 Genotype : T. guttata Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol, ix, 312 and key. 



Fam. 11. ALAIMIDAE Micoletzky, 1922. 



Free-living forms, mostly marine, but sometimes terri- 

 colous or fresh-water. Buccal cavity absent or extremely 

 small. Oesophagus generally without a true muscular bulb 

 containing valves. Reproductive organs simple. Sexes 

 generally distinct. Oviparous, producing few and large 

 eggs. 



Micoletzky (1922) proposes to divide this family into two 

 subfamilies, Alaiminae and Leptosomatinae. The distinction 

 between these subfamilies is that in the latter a ventral 

 excretory gland, or lateral canals and an excretory pore, are 

 present, while they are said to be absent in the former. It 

 is scarcely credible that there are any forms without some 

 such structures, though they may occasionally be very hard 

 to detect. We have therefore felt it unjustifiable to retain 

 the proposed subfamilies. 



1, Alaimus de Man, 1880. 



Cuticle unstriated, without bristles or lateral alae. Head 

 not distinct, without bristles. Lips absent. Oesophagus 

 elongate, expanding gradually behind. Caudal end of male 

 usually with a median row of three to five preanal papillae. 

 No accessory piece present. Testis single. Female genital 

 tube single, posterior. Sometimes parthenogenetic. No 

 caudal glands or spimaeret. 



Hab. Soil and plant-roots. 



Genotype : A. primitivus de Man, 1880. 



de Man, 1880, Tijdschr. Nederl. dierk. Vereen., Leiden, 2 ; 

 1884, Die frei . . . lebenden Nematoden der Niederl. Fauna, 

 29; Micoletzky, 1922, Arch. f. Naturg., Abt. A, Ixxxvii, 134. 



