268 



ORDER ISOLAIMIA 



4.8 10.2.... 16. "-54-" 86. g __ 



53a. Pseudolella cephalata n. sp. !> 8 i*"" 5j '3.V 2.7 '' " Cuticle naked; 

 wings optically expressed in the form of closely approximated, indistinct longi- 

 tudinal lines. The unusually long amphids are of such a character as to be 

 mistaken at first for wings. Behind the neck the amphids gradually narrow, so 

 that somewhat in front of the middle of the body, where they end, their width 

 is only about one-third as great as opposite the base of the pharynx. Neck 

 conoid. Cuticula much thinner on the head. Lips thick ; six, or three and two- 



SSt(J)h(4) 



parted. Internally the lips are armed with six very minute 

 odontia (?), apparently having an outward stroke. From 

 the expanded base of the pharynx muscular fibres are seen 

 passing to the front, clearly indicating that the entire struc- 

 ture can be moved forward; such movement would be 

 entirely in accord with the structure of the labial region. 

 The oesophagus maintains the same diameter until after it 

 passes through the nerve-ring; it then expands rather rap- 

 idly so as to form the pyriform cardiac bulb nearly two-thirds 

 as wide as the base of the neck. There is a flattish-conoid 

 cardia, one-third as wide as the base of the neck. The front 

 end of the intestine is pressed to one side by the strongly 

 developed renette cell, but behind this cell it becomes about 

 two-thirds to three-fourths as wide as the body; its cross- 

 section probably is composed of six or more cells. These 

 cells contain scattered yellowish to brownish granules of small but variable size. 

 The anus is rather inconspicuous. The rectum is about as long as the anal body 

 diameter. The tail is at first conoid, so that at a distance from the anus equal 

 to five times the anal body diameter, its diameter is not over one-sixth as great 

 as at the base. The remainder of the tail, probably a short part only, is missing. 

 Caudal glands probably located in the base of the tail. The renette cell, half 

 as wide as the body and about twice as long as it is wide, is located behind the 

 base of the neck a distance equal to two body diameters. From the slightly 

 elevated vulva the rather massive vagina leads inward fully half way across the 

 body. About eight ova are arranged single file in each ovary. The eggs are 

 two to three times as long as the body is wide, and a little less than one-third as 

 wide as long. The spermatozoa seen in the uterus are about one-sixth as wide 

 as the body, and are finely granular and have their chromatin in an ellipsoidal 

 form surrounded by a clear area. 



Habitat: Punta Arenas, Pacific Coast of Costa Rica. The following are the 

 actual measurements in microns: n ?s._ m. '"-4ior"' 658 Fig. 53o. 



./ *^ :: '.- ;.'".' M'* 900 - ..... 



b. Pseudolella granulifera n. sp. Type species. Cuticle as in P. cephalata, 

 but without wings. Neck convex-conoid anteriorly ; especially at the head, which 

 is somewhat bluntly pointed. Cephalic setae four, arcuate, spreading, and one- 

 third as long as the corresponding diameter of the head, arranged about one- 

 fourth of the distance back to the beginning of the tubular portion of the pharynx. 

 Lips confluent, obscure, probably three in number. No labial papillae seen. 

 Amphids long, slender; beginning some distance behind the pharynx and extend- 

 ing forward in the form of a band or groove about half as wide as the pharynx, 

 and having refractive cutinized edges. This band extends to very near the lips, 

 then suddenly narrows and turns back on itself and ends indefinitely in front of 



