3. The same. Perineum. _a_, penis. _b_, rudimentary mammary slits. _c_,
anus. About ¼ nat. size.
4. _Mesoplodon stejnegeri._ Yaquina Bay, Oregon. Cat. No. 143132,
U.S.N.M. Head, showing teeth in natural position.
[Illustration: Plate 41 MESOPLODON AND ZIPHIUS]
Fig. 1. _Mesoplodon europæus._ Atlantic City, New Jersey. Male, young.
Cat. No. 23346, U.S.N.M. Length 12½ feet.