A REVIEW OF THE APODAL FISHES OR EELS OF JAPAN, WITH DESCRIPTIONS OF NINETEEN NEW SPECIES. By David Stark Jordan and John Ottkrrktx Snyder, Of tlic Liiand Stanford Junior Vnlvcrxilij. In the following-papcM-is g-iyen an account of the species of apodal or eel-like lishes known fi-oiu the waters of Japan. The paper is based on the collection made by the authors in the waters of Japan during-the sunnner of r.»(>0. luider the auspices of the Hopkins Seaside Laboratory, the series of Japanese tishes l)elonging to the LTnited States National Museum, and specimens collected by the United States Fish Commission steamer Alhatross. The collection made by the authors is in the museum of Leland Stanford Junior Universit}", a series having been also deposited in the United States National Museum. The accompanying drawings are the work of Miss Lvdia M. Hart. Th(^ apodal fishes agree in the eel-like form of the body, the d(\grada-tion of tile skeleton, arid the detei'ioratioti of the rins and thiMV basal segments. Among the apodal lishes of Japan two orders are recognized; one, Si/riil>r(nicJu<(, has the structure of the mouth characteristic of ordinary tishes; the other, Apodcs^ has the })remaxillaries atro]>hied or lost. Order SVMBRANCHIA. Body eel-shaped; premaxillary, maxillary, and palatine bones well developed and distinct from each other, as in ordinary tishes. Shoulder girdle joined to the skull in typical species (in one famih^, Amplitp-noida'^ distinct from the skull as in the eels). No mesocoracoid; symplectic present or absent; scales minute or wanting; no paired tins; vertical tins rudimentary, reduced to folds of th(^ skin; vent at a great distance from the head; gill openings confluent in a single slit; no air bladder; stomach without blind sac or pyloric cteca; ovaries with ovi-ducts; skull solid, the l)ones linuly united; vertebne numerous, the Proceedings U. S. National Museum, Vol. XXIII— No. 1239. 837