142 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



The uteri are divergent. The ovaries are large and club-shaped in 

 the adult. Their average diameter is 0.070 mm. 



The eggs are segmented in utero and the uteri may contain many 

 or few eggs, depending upon the degree of maturity. The eggs (fig. 7) 

 are large, with thin clear shells, ellipsoidal, and with an asymmetrically 

 flattened surface on one side. The eggs range from 0.182 to 0.210 mm. 

 in length by 0.077 to 0.098 mm. in width. The average size is 0.192 

 mm. by 0.089 mm. 



SPECIFIC DIAGNOSIS OF ALAEURIS GALAPAGENSIS 



Principal characters of genus. Oxyurids of medium size; males from 

 2.75 to 3.80 mm. by 0.20 to 0.30 mm. ; females from 4.52 to 6.49 mm. 

 by 0.39 to 0.47 mm. Thin cuticula, striations 0.005 mm. apart. No 

 cervical or lateral alae; caudal alae in male. Cephalic region distinct 

 and truncate; mouth surrounded by three simple lips. Ten cephalic 

 papillae and two amphids present; papillae in two circles; ventrolateral 

 lips each with four papillae and an amphid ; dorsal lip with two papillae, 

 and a median anterior toothlike projection. Buccal cavity present con- 

 taining six toothlike projections from anterior end of esophagus. Nerve 

 ring about 0.22 mm. in male and 0.26 mm. in female from anterior 

 end. Excretory pore prebulbar, about 1.03 mm. in male and 1.69 mm. in 

 female from anterior end. Esophagus long and slender, about one half 

 body length in male and one third body length in female. Intestine 

 rectilinear, enlarged anteriorly into a bulb. 



Male: Bluntly rounded tail, 0.11 mm. long; wide caudal alae from 

 base to distal fourth of tail. Spicule from 0.415 to 0.589 mm. in length, 

 sharply pointed. Accessoiy piece well developed, 0.046 mm. by 0.076 

 mm. Four pairs of genital papillae; three pairs circumcloacal, of which 

 two pairs are sessile, one pair pedunculated; one pair pedunculated 

 caudal papillae at point alae join tail. 



Female: Straight pointed tail 0.57 mm. long. Vulva posterior to 

 mid-body, 2.97 mm. from anterior end. Vagina very muscular, ovejector 

 less muscular, connected to divergent uteri by a common uterine stem. 

 Short oviducts connect large club-shaped ovaries to uteri. Eggs large, 

 ellipsoidal, flattened on one side; measure 0.192 mm. by 0.089 mm.; 

 segmented in utero. 



This species is named for Its geographic location, the Galapagos 

 Islands. 



