Nematodes from the Summit of Long's Peak, Colorado Author Thorne, Gerald text Transactions of the American Microscopical Society 1929 1929-04-30 48 2 181 181 http://dx.doi.org/10.2307/3222211 journal article 10.2307/3222211 Aphelenchus pusillus n. sp. Diagnosis: ** Characters somewhat similar to Aphelenchus parietinus Bastian but with these differences: Body only. 31 mm. in length. Spear much larger with distinct trilobed base. Tail ending in a mucro formed by a sudden contraction of the terminus. * For explanation of the decimal formula, Cobb. in these Transactions, Vol. XXXIII, see page 73. ** The “ Diagnosis” includes the decimal formula of the measurements of the species and the first paragraph following the formula. The additional paragraphs give general, but not specific, information. The transverse stiae are exceedingly fine, being scarcely visible. There are two very indistinct wings. The lip region is set off and has a cutinous framework about the entrance to the pharynx. A narrow vestibule reaches half the spear length, at its base forming an indistinct guiding ring for the spear. The median bulb is as long as the neck width and almost as wide as the body cavity with a conspicuous valvular apparatus near its center. The nerve ring encircles the narrow tube leading from the bulb to the intestine one body width below the bulb. The renette pore is opposite the nerve ring. The anus is distinct and from it the slender rectum extends forward two anal body-widths. A prominent feature is a ventral narrowing of the body just posterior to the elevated vulva. Whe anterior ovary is out-stretched the posterior rudimentary and only three body-widths long. Eggs are three times as long as the vulva body-width and fill the body cavity. Five specimens, all of which are adult females. Fig. 2 a-b. 1000x.