At the request of Dr K. P. Schmidt, Chicago, I recently examined the types of Psammophis antillensis Schl. This species as originally described was a composite, and it is, therefore, necessary to select a lectotype to restrict the name antillensis to one of the species involved. The difficulty is that Schlegel did not label his types as such, and that in most cases he did not mention how many specimens he actually examined. From the introduction to his Essai we know that Schlegel visited Paris, that the collections of the Museum National d'Histoire Naturelle were placed at his disposal, and that he was allowed to take the undescribed species with him to Leiden for further studies (Schlegel, 1837, I, p. XXIV). What happened in the case of Psammophis antillensis is probably this: in Paris Schlegel examined a series of snakes, which he believed to belong to an undescribed species; from this series he selected a few specimens which were taken to Leiden, and on these latter the description was based. The first point which must be settled is what specimens we are to consider as cotypes. In the present case there are two possibilities: 1. only those specimens upon which the description was actually based are cotypes; 2. all the specimens which were examined by Schlegel at Paris, as well as those at Leiden are cotypes 2). There is something to be said in favour of both points of view, but I believe that in the present case where a lectotype must be established only the specimens mentioned sub 1 must be taken into consideration. I do not think that there need be any doubt that the specimens which were presented to the Leiden Museum were before Schlegel when he drew up the description. As