Length of dentary 400 millim. Depth opposite the first tooth 20 Depth opposite last tooth 62 Entire extent of mandible 630 Greatest depth at coronoid process 95 2. Length of axis with odontoid process 80 Length of axis without odontoid process 70 Vertical diameter of ball 24 Transverse diameter of ball 33 4. Length of fourth cervical vertebra to rim of ball 49 Expanse of diapophyses 82 5. Length of fifth cervical to rim of ball 49 Transverse diameter of ball 35 Vertical diameter of ball 28 Expanse of diapophyses 90 8. Length of eighth vertebra to rim of ball 53 Expanse of diapophyses 90 14. Length to rim of ball 54 Transverse diameter of ball 40 Vertical diameter of ball 33 Expanse of diapophyses 100 18. Length to rim of ball 50 Transverse diameter of ball 40 Vertical diameter of ball 36 Expanse of diapophyses 100 23. Length to rim of ball 50 Transverse diameter of ball 41 Expanse of diapophyses 100 25. Length to rim of ball 52 Transverse diameter of ball 43 Vertical diameter of ball 43 Expanse of diapophyses 100 30. Length to rim of ball 54 Transverse diameter of ball 46 This species is named in memory of Judge E. P. West, lately deceased, to whom our Museum owes so much for his long, diligent and faithful labors in the collection and preparation of the geological material. * * * * * ERRATUM: P. 17, line 15, for “_Edestosaurus_,” read _Clidastes_, and in next line, strike out “Proc. Acad.” etc. Notes and Descriptions of Syrphidae. BY W. A. SNOW. WITH PLATE VII.