Fig. 16a. Cecidomyia sp. Variety, new. × 5. Fig. 17. Caryomyia persicoides. Beut. × 5. Fig. 18. Cecidomyia sp. × 4. Fig. 19. Cecidomyia sp. New. × 4. Fig. 20. Caryomyia caryae O. S. × 5. Fig. 20a. Caryomyia caryae. Large specimen. × 5. Fig. 21. Caryomyia holotricha O. S. Isolated specimen. × 5. Fig. 21a. Caryomyia holotricha O. S. Aggregate condition × ⅔. Fig. 21b. Caryomyia holotricha O. S. Bilocular unit of aggregate form. × 2. Fig. 22. Cecidomyia sp. New. × 5. Fig. 23. Cecidomyia sp. Possibly new. × 5. Fig. 24. Caryomyia similis Felt (?) × 1. Fig. 25. Cecidomyia sp, Caryomyia caryae O. S. (?) × 5. Fig. 26. Caryomyia tubicola O. S. × 3. Fig. 27. Cecidomyia sp. New. × 3. Fig. 28. Cecidomyia sp. New. × 5. Fig. 29. Cecidozoon (undetermined). New. × 3. Fig. 30. Cecidomyia sp. New. × 7. Fig. 31. Cecidomyia sp. New. × 6. Fig. 32. Cecidomyia sp. × 5. Fig. 33. Cecidomyia ? sp. × 5. [Illustration: OHIO JOURNAL OF SCIENCE. VOL. XVI. PLATE I.] [Illustration: OHIO JOURNAL OF SCIENCE. VOL. XVI, PLATE II.] [1] Contribution from the Botanical Laboratory of the Ohio State University, No. 92. [2] Pergande, T. “North American Phylloxerinae affecting Hicoria and other Trees.” Proc. Davenport Acad. Sci. 9:185-271, pls. 1-21. 1903. [3] Felt, E. P. “The Identity of the better known Midge Galls.” Ottawa Naturalist, Vol. 25, Nos. 11, 12. 1912. [4] Küster, E. Die Gallen der Pflanzen, Leipzig. 1911. [5] Cook, Mel T. “Galls and Insects Producing Them.” Ohio Nat. 4:140-141. 1904. THE GEOMETRY OF THE TRANSLATED NORMAL CURVE. CARL J. WEST, Ph. D. =Introduction.= In curve tracing the graphic representation is constructed from the equation. Due largely to the requirements of statistics the converse, namely, to find the equation of the curve when the distribution of points is given, has become of interest. This problem is very different from the exercises of analytical geometry in which a given law of distribution of points is to be translated into algebraic language. For the presence in the statistical data of accidental irregularities makes it undesirable as well as practically impossible to obtain a curve passing _through_ the points. Instead, a curve is “fitted” to the points, that is, a curve is passed _among_ the points in accordance with some generally accepted principal such as that of least squares or the agreement of moments. Aside from the straight line and the parabolas, the curves proposed by Pearson[6] have found acceptance. In order to derive curves which can be fitted to widely varying distributions of points, Professor F. Y. Edgeworth[7] has proposed to modify, to _translate_, the normal probability curve with unit standard deviation. 1 y = —————— e^(—(t^2/2)) √(2π)