Lagochilascaris sprenti sp. n. (Nematoda: ascarididae) from the opossum, Didelphis virginiana (Marsupialia: didelphidae).

Sixty-eight specimens of Lagochilascaris from the stomach of seven naturally-infected opossums from Louisiana were described as Lagochilascaris sprenti sp. n. Observations were also made on adult worms of both sexes recovered from experimentally-infected opossums and mice. The new species differs from the four previously described species of Lagochilascaris in the length of the spicules, number of pits on the circumference of the egg, and position of the vulva. The spicules are shorter in L. sprenti than in L. turgida and L. buckleyi. The number of surface pits in the eggshell at the circumference of the egg is 24 to 31 in L. sprenti, less in L. minor (15-26), and more in L. major (33-45). In worms of equal length, the vulva is consistently about 1 mm further anteriad in L. sprenti than it is in L. minor or L. major.