302 



ORDER TRIPLONCHIA 



arm 



tinuous, the rectum inconspicuous and about as long as the anal body diameter. 

 The nuclei of the intestinal cells are clear, and have twice the diameter of the 

 largest intestinal granules, and present a nucleolus. The cells of the intestine 

 are usually packed with granules of variable size, the largest of which are one- 

 ninth as wide as the body and are so arranged as to give rise to a more or less 

 distinct tessellated effect. Tail of the adult, as shown in the illustration. The 

 tail of a larva is more or less cylindroid, but slightly conoid and at the end bluntly 

 rounded and almost imperceptibly apiculate. There are no caudal glands. 

 i ^PP site the base of the oesophagus, 

 ..... there are two to three nuclei similar to 

 those often found in the genera Tylen- 

 .CUt chus and Aphelenchus, and probably hav- 

 ing the same function, namely, that of 

 salivary glands. The long renette, which 

 LSImUt appears to be sometimes on the right, 

 sometimes on the left, extends back along 

 the lateral field a long distance; it has 

 been followed for three-fourths the length 

 of the body. The nerve-ring is accom- 

 dl panied by rather obscure nerve cells. 

 Only the blind end of the tapering ovary 

 ^ - is reflexed. The vulva is large and con- 

 spicuous, and is somewhat elevated, espe- 

 cially in front. The straight uterus contains ellipsoidal to elongated eggs, which 

 are about as long as the body is wide, measuring forty by twenty-five microns. 

 They begin segmenting before deposition. 



Habitat: Found at Falls Church. Va., U. S. A., parasitic in a wood-boring 

 beetle, determined by Mr. F. C. Craighead as Cyllene picta Drury. Sixteen 

 thousand larvae and a few adult females were found in one beetle. Both male 

 and female beetle are infested, usually with only a few female parasites ; at least 

 such is the condition in the month of May. Of fourteen female insects, three 

 were infested; of twelve males, seven were infested. As a rule, only a few adult 

 females of Aphelenchulus mollis occur in one host, about one to eight. Two 

 living adult males of Aphelenchulus mollis were found in the castings of beetles 

 taken from infested logs. These are the only adult males so far seen. This 

 finding may indicate that the females are fertilized before entering the host. 

 The parasites are found in the thorax of the beetle, as well as the abdomen. Fig. 

 81a, p. 301; Fig. 816. 



.4 . 14. -88. 92. 



gmm 



82. lotonchium imperfectum (Butschli) nom. nov. t- 6 '* 'A, '!' 2 -5 

 Striae fine; contour entire. Head abruptly truncate, set off by expansion. Spear 

 exceedingly minute, eight microns long, about one-fourth to one-fifth as long as 

 the head is wide, simple, plain, apparently not bulbed; in the male, the spear is 

 difficult to see, being reduced to a mere point. Neck conoid; amphids?. Intes- 

 tine very transparent; anus indistinct. Tail of the female conical from the vulva, 

 acute. Excretory duct single, much coiled. Ovary outstretched forward; eggs 

 somewhat longer than body is wide, half as wide as long, deposited after segmen- 

 tation. Spicula L-form, tapering, cephalated by constriction, considerably 

 longer than the anal body-diameter; accessory pieces none; bursa well-developed, 

 springing from considerably in front of the spicula and extending somewhat 

 beyond the terminus. 



Habitat: In rotting fungi, Germany. Syn. Tylenchus imperfeclus Btsli. 



