THE LIFE HISTORY OF A TREMATODE (LEVINSENIELLA CRUZI?) FROM THE SHORE BIRDS (LIMOSA FEDOA AND CATOPTROPHORUS SEMIPALMATUS INORNATUS)

¹ From the Scripps Institution of Oceanography, La Jolla, California

The life history of a trematode (Levinseniella cruzi?) from the shore birds (Limosa and Catoptrophorus) and the structure of its cercaria have been described in some detail. The probable life history is as follows:

The miracidium has not yet been certainly observed. The cercaria, which belongs to the ubiquita group of Lebour, inhabits the snail, Olivella biplicata. From here it passes to the sand crab, Emerita analoga, which latter, when eaten by the birds, infests them with the adult trematode. The degree of infestation of the snail is considerable, but the cercarial are shed infrequently, possibly at definite seasons.

Practically all crabs over 6 to 7 mm. in length are infested, but for some as yet undetermined reason, the infestation of the birds is light.