While studying the undetermined sawfly material in the Cornell University insect collection, the author discovered what he believed to be a species new to science in the genus Neurotoma. This belief was kindly confirmed by Dr. H. H. Ross who said that he likewise had a single specimen. Since that time four years ago, the author has collected this same species in considerable numbers and has also collected the larvae from the host plant which is Crataegus sp. It is therefore proposed to name it Neurotoma crataegi.