Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 24. (Budapest 1926)
Éhik, Gy.: Magyarország földipockai
In order to eliminate these difficulties, I had to modify my measurements. I measured the palatinal depth of the brain-case together with the auditory bullae, so that 1 took the skull between te fingers of the micrometer by setting one of its fingers on the lower edge of the set of teeth and the auditory bullae. Along this diagonal it is comparatively easy to measure the depth of the brain-case even without the bullae, if we take the brain-case between the fingers of the micrometer by setting one of the pointed ends of the latter into the mesopterygoid space (fossa interpterygoidea). The difference between the two dimensions gives accurately the height of the auditory bullae. I measured finally the occipital depth of the brain-case from the back edge of the basioccipital up to the highest point of the occipital bone. I added the depth of the tympanon bone after having calculated it to that height, and I figured with the depth gained this way. My dimensions gained this way are nearer to the results of MILLER'S calculation. It remains, of course, still an open question whether our figures correspond to facts. To my opinion, a difference of ö7o in index numbers, considering the possibilities for immense errors, can not be applied in determinations as a sign distinguishing for undergroups. I regret not to be able to recommend for the time being a better method for that. MÉHELY considers the genitalia as a criterion for the determination of a species of mammals 1 , and he pays attention especially to the morphology of the penis in the determination of the species. I made my researches according to the opinions of MÉHELY on the penises of Hungarian Pitymys-es and the results of my general researches have been the following : 1. The external morphology of the penises of my specimens from the same locality can differ. According to the opinion of MÉHELY we have to consider them different species or at least different varieties in that case. 2. The morphology of the penis of one Microtus arvalis investigated by me is quite identical with the morphology of the penis of several Hungarian Pitymys-es. As the above facts contradict the opinion of MÉHELY, I dropped the description of the penises in the description of the single species. I shall publish the detailed results of my research undertaken with the penises in the frames of a separate paper. 1 MÉHELY: Die Streifenmäuse (Sicistinae) Europas. (Ann. Mus. Nat. Hung. XI, 1913, p. 220—256).
