In the Proceedings of the Zool. Soc. of London for this year (1884) Mr. Beddard wrote a very interesting paper regarding some points of the structure of Hapalemur simus. On page 392 he says a few words touching the differences between the skulls of H. simus and H. griseus. He says that he was able to verify the late Gray’s statements (with regard to the differences in the skulls of the two species) with a single exception, and finally states that it seems to him that Gray was right in believing that Schlegel’s figure of the skull of Hapalemur griseus was in reality that of Hapalemur simus. Being able to settle this question it seems to me that it is my duty to fixe for a moment again the attention of the naturalists upon this matter.