200 Mr. II. A. Baylis on some 



Moasurenients (in mm.), taken from two males aiul three 

 mature females: — 



6. $. 



Lengrth Tj-o 6 5-52-6 



Thickness— at crown of hairs 0'()33-00.'17 0-0.37 



„ at base of o?sophagus . 0-lo-0-l(3 014-0-16 



„ at middle of bo Iv 0-22-0-2-i 019-0-25 



„ at anus " 009 009-0-1 



Length of wsophagus 0-8-0-93 0-81-0-9 



„ tail 0-33-0.35 0-4-0-5 



,, spicules 0-12-015 .... 



Distance from head-end to excre- 

 tory pore 0-065 00625-0-075 



Distance from head-end to nerve- 

 ring 0-40-0-44 0-39-0-42 



Distance from head-end to vulva . .... 1-41-1*65 



« 23-6-25 22-2-29 



^ 6-4-6-5 6-6-6-8 



y 



15-7-17 11-1-13-8 



Tlie body tapers considerably both anteriorly and poste- 

 riorly, the neck especially being very slender. Posteriorly 

 the tapering begins a little in front of the anus. The cuticle 

 is quite smooth, no transverse striations having been detected. 

 In the male only there are a few slender hairs (fig. 2, p. 292) 

 on the ventnil surface in front of and behind the anus, and 

 a few shorter and more scattered hairs on the tail. The 

 lateral fields are of a coarsely cellular appearance, and 

 measure 0'025 mm. in width. 



The head (fig. 1) is very narrow. Near the extremity 

 there is a crown of six stoutish bristles, which stand out at 

 right angles to the long axis of the body, their tips curving 

 furward. Two of the bristles are lateral, two subdorsal, and 

 two subventral. The chief peculiarity of the species is the 

 fact that instead of the pair of circular or spiral lateral organs 

 near the anterior end, cliaracteristic of the majority of free- 

 living nematodes, there apj;ear3 to be on either side a longi- 

 tudinal row of thirty or more very small pits in the cuticle 

 (fig. 1, L.), which may pos.sibly be regarded as " lateral 

 organs." They are situated just above the level of the lateral 

 field on either side, and are, therefore, subdorsal in position. 

 De Man (1884, pi. i. figs. 3, 3 a, 3 d) figures a row of organs 

 in Deontoiaimus papillatus, which would appear, from the 

 figures, to be of a somewhat similar nature. According to 

 his account of this species, however (1884, p. 32), they are 

 " jjapillaj" rather than pits, and occur, in the male onJy, in a 

 sinj^le median ventral row extending throughout the whole 



