174 (S ' 



THE MONONCHS 



46. M. digiturus Cobb. Amphids occur opposite the anterior part of the 

 pharynx. What appears to be a renette pore occurs just behind the nerve- ring. 

 The anal region 3.3 8 . 26. 70 12 92. 

 is somewhat 



1.4 



in.. 



3. 3.4 3.4 2.3 



raised. Behind the anus the tail diminishes rapidly 

 in diameter, so that at the end of the anterior fourth 

 it is about three-fifths as wide as at the anus. 

 Thence, for some distance it is cylindrical, but be- 

 comes somewhat abruptly convex-conoid in the pos- 

 terior fifth and ends in a rather narrow, inconspicu- 

 ous .spinneret. The lining of the oesophagus is a con- 

 spicuous feature. Intestine not tessellated. The 

 longitudinal ribs of the inner wall of the pharynx 

 are rather conspicuous features, and extend from 

 end to end of the pharynx. 



Found about the roots of banana plants, Fiji. 

 Fig. 58. . 



47. M. trichurus, n. sp. This outstanding form has an oesophagus that is 

 slightly swollen where it receives the pharynx. The lining of the oesophagus is 



2.6 7. 21. '52 11 67. prominent, occupying 



2.3 . 2.4 278 279 1.8 l " * three-fifths of the op- 

 tical section. Longitudinal fields one-fourth as wide as the 

 body. Characters well set forth in fig. 14, p. 146. 



Found about the roots of orange trees, Bahia, Brazil. 

 Bears considerable resemblance to M. gymnolaimus. It ap- 

 pears possible from these investigations that the tropical 

 mononchs, when more fully known, will prove especially 

 interesting. Nearly all the more striking species here re- 

 corded are from the tropics. The warm soils of the tropical 



regions teem with nematodes, many of 



them no doubt, especialy adapted to the 



peculiar conditions found there. The 



predatory mononchs in such soils will 



naturally enough have responded in 



structure not only to the climatic con- 

 ditions, but also to the form and habits 



of their quarry. Fig. 59 (just above). / i' : :$Viar "" 



48. M. gymnolaimus Cobb. The 

 more or less triquetrous pharynx is 

 strongly three-ribbed. Cardia of such 



2.6 6.8 24. '67 16 86. 



2.S mm 



2.2 2.3 2.7 2.5 1.6 

 a nature as to give rise to a double 

 constriction in the cardiac region. In- 

 testine about 12 cells in girth. What 

 appears to be a renette pore occurs 

 immediately behind the nerve-ring. 

 The lateral fields are about one-fifth 

 as wide as the bodv. The tail tapers 

 regularly to near the terminus ; it is, 



however, cylindroid for a short distance in front of the spinneret. Vulva not 

 prominent. The uterus is as long as the reflexed portion of the ovary, which 



