"(1) The characters in question are, in the sense used, problematical, inasmuch as no examination can be made of the soft parts of extinct forms, but with equal force may it be urged that any characters that have not been or cannot be _directly_ confirmed are problematical in the case of all other groups (e.g., mammals), and it can only be replied that the coordination of parts has been so invariably verified that all probabilities are in favor of similar coordination in any given case. "(2) There is doubtless considerable difference in the number of valves of the _bulbus arteriosus_ among the various Ganoids, and even among the species of a single family (e.g., _Lepidosteidæ_), but the character of Ganoids lies not in the number, more or less, but in the greater number and relations (in contradistinction to the opposite pair of the Teleosts) in conjunction with the development of a _bulbus arteriosus_. In no other forms of Teleostomes have similar relations and structures been yet demonstrated. "(3) The failure of the spiral intestinal valve has already been conceded, and no great stress has ever been laid on the character. "(4) The chiasma of the optic nerves is so common to all the known Ganoids, and has not been found in those forms (e.g., _Arapaima_, _Osteoglossum_, and _Clupeiform_ types) agreeing with typical physostome Teleosts in the skeleton, heart, etc., but which at the same time simulate most certain Ganoids (e.g., _Amia_) in form. "Therefore, in view of the evidence hitherto obtained, the arguments against the validity of title, to natural association, of the Ganoids, have to meet the positive evidence of the coordinations noted; the value of such characteristics and coordinations can only be affected or destroyed by the demonstration that in all other respects there is (1) very close agreement of certain of the constituents of the subclass with other forms, and (2) inversely proportionate dissimilarity of those forms from _any_ (not all) other of the Ganoids, and consequently evidence _ubi plurima nitent_ against the taxonomic value of the characters employed for distinction.