Trichuris Species from California Rodents

Abstract

Specimens from Thoimomys bottae bottae are larger than those described by Hall, 1916, from Thomomys fossor in Colorado, the males measuring 28 to 30 mm in length, and the females 28 to 33 mm. In Hall's specimens, which were probably immature, the anterior portion of the body exceeded the posterior portion in length, but in my mature specimens the posterior portion equals or exceeds the anterior portion in length. The specimens agree in the bilobed end of the male body, the bell-shaped, spiny, spicular sheath, and the length of the spicule (about 1.5 mm long in my specimens). The spicule flares slightly a short distance behind the tip. The cloacal tube is about 2.5 mm long, and is joined by the spicular tube near the middle of its length. The ejaculatory duct joins the vas deferens at about the middle of the length of the posterior portion of the body. In the female the vulva is not situated on a prominence, and the ovejector is from 1.1 to 2 mm long, gradually widening into the uterus. The anus is subterminal. The eggs, not seen by Hall, are relatively broad, measuring 64 to 68 microns by 35 to 38 microns.