HIRUDINEOS DE MEXICO. XI

Resumen

As Doctor Asajiro Oka, we have also found, in the Lakes of Xochimilco and Chapultepec, examples of Glossosiphonia fusca. Our study leads us to consider for this species XXVI somites in stead of the XXVII that Castle and Moore found; this difference is due to the fact that the North American authors begin the count the somites from the first ring and we, in accord with R. Blanchard, from the first pair of eyes, considering these as the first pair of segmentary papillae.