118 



NOTES OX XEMAS 



Recently I have discovered that the principal cephalic organs are 

 made up of segments which, while simple in character, bear no small re- 

 semblance to correspond- 

 ing features in segmented 

 organisms. The nature of 

 these segmented append- 

 ages will be more easily 

 understood by consulting 

 the illustrations in Fig. 2. 

 The articulations in the 

 TJ&&KS25^^ cephalic organs of nemas 



are not easy to discover, 



owing to the small size of the organs and the transparency of the tissues. 

 Some of these segmented organs are under muscular control, and can 

 be extended and inflexed. 



This is true of some of the setcphyntr [ (| set Jit /] J set /pli t'xt 

 labial organs, which un- 

 fortunately are usually so 

 small as to be difficult to 

 observe. The cephalic 

 setae, however, are larger, 

 being particularly well de- 

 veloped on some marine 

 forms, and in this case ob- 

 servation on living speci- 

 mens affords evidence of 

 the articulations when they 

 might be overlooked if 

 they were sought by other 

 methods; for if a seta is 

 obstructed it takes on the 

 attitude natural to an or- 

 gan composed of flexible 

 joints and more or less in- 

 flexible segments, as shown 

 in the upper illustration, 



.g., n.sp., a nema with 

 bling Cyatholaimus, but 



. Fig. 3. Pomponema mirabile n 



Jig. 2. Here again, Once jointed cephalic organs, and resem 



with 3 onchi, more complicated amphids, long, jointed, 

 labial palps, wings as in Spilophora, spicula as in Cyatholaim- 

 us, with 20 chromadoroid, male supplementary organs. 

 Characters of P. mirabile, type species, given in the illustra- 

 tions and formula. 



. 

 having established the fact 



and learned hOW tO make 

 . . . . 



the observations, it proves 



that the setae of a wide range of genera are jointed, though the 



number of segments is often reduced to only one or two. 



