NEMATODOS DE LOS AJOLOTES DE MEXICO I

Resumen

With the present paper we begin the helminthological studies of the "Ajolotes" typical bathrocius of the fauna of Mexico. 
We redescribe briefly Spironoura elongata (Baird, 1858) and give a careful and detailed description of Hedruris siredonis Baird 1858 with special reference to the variability of the papillar system.