which are normal in this respect. This fact, along with his 

 observations of the primitive condition of the "circulus 

 cephalicus" vessels in Lactophrys and Balistes (the only 

 scleroderms in which he was able to examine the vas- 

 cular system) and of its highly specialized condition in 

 the gymnodonts, led Rosen (1912:19) to comment on 

 "the occurrence of a great number of both primitive and 

 highly specialized characters not only within the group 

 but also in the same form." Thus, he felt that "Judging 

 from the number of primitive characters that we have 

 found in some Plectognaths we have all reason to believe, 

 that this fish group has branched off rather early from 

 the Teleostean main stock" (1912:20). 



On matters of osteology, and considering that he had 

 examined only four species of Plectognathi, Rosen's ob- 

 servations were generally quite accurate. He was able to 

 substantially improve our knowledge of the plectog- 

 naths and to correct one of Regan's major errors. Regan 

 had said in his diagnoses of the Sclerodermi and Gym- 

 nodontes that the former had all of the neural arches 

 forming single spines, while in the latter the anterior 

 vertebrae had bifid neural spines. Rosen correctly 

 pointed out that in balistoids the first vertebra has a bifid 

 neural spine and no bony roof over the neural canal. One 

 would probably disagree, however, with Rosen's assess- 

 ment of Regan, whose contribution Rosen (1916a:l) said 

 "does not seem to me to have increased our knowledge 

 either of the skeleton or of the phylogeny of the group." 

 Rosen's description of the developmental and adult 

 cranial osteology of Sphoeroides was well done, for he de- 

 scribed it with more precision than had been given to a 

 plectognath up until that time. But like Regan before 

 him, Rosen included very few figures of the structures he 

 discussed so well. However, since Rosen described these 



was not until 3 years after he had finished his manuscript 

 that he had seen Rosen's first three articles. Kaschkaroff 

 (1914a:365) simply said that he found them "sehr in- 

 teressante." Whereas only a small, but highly sig- 

 nificant, part of Rosen's output was devoted to osteology, 

 the majority of Kaschkaroff s work concerned the os- 

 teology of the plectognaths and the histology of their 

 bones, and only minor excursions were taken into soft 

 anatomy. In this respect Kaschkaroff s treatment of the 

 order was similar to that of HoUard. Whereas HoUard 

 produced the first work that could be called a monograph 

 on the osteology of the plectognaths, Kaschkaroff 

 produced what until now is the last such work. 



Kaschkaroff began his study at one of the end points of 

 plectognath radiation, for he (1914a:265) admitted that 

 "Meines Erachtens ist Orthagoriscus mola die interes- 

 san teste Form genannter Gruppe." That view has many 

 advocates, as attested to by the practically infinite num- 

 ber of distributional and natural history notes that have 

 been devoted to that species. Kaschkaroff proceeded to 

 describe, with many more illustrations than had Rosen, 

 the general osteology of members of all the major groups 

 of plectognaths, with the exception of Triodon, of which 

 he had no specimens. While on the whole Kaschkaroff s 

 work is highly valuable, it contains a number of serious 

 observational errors that will be mentioned in the os- 

 teological section of this monograph. Regardless of os- 

 teological errors, Kaschkaroff had intelligently examined 

 a large number of plectognaths and the conclusions at 

 which he arrived are important to note. These con- 

 clusions were best summarized in the diagram he 

 presented (1914a:359), while cautioning the reader that 

 this was only a chart of anatomical similarity and not 

 necessarily a phylogenetic tree. 



Tetrodon Diodon Triodon Orthagoriscus Balistes Monacanthus Ostracion 



Triacanthus / 

 Der Vorfahr 



structures in some detail, it is not overly difficult to 

 reconstruct what he saw. The same cannot be said of 

 Regan's telegraphic summaries of his osteological obser- 

 vations. 



In the middle of the 4-year period during which 

 Rosen's series was published, there appeared Kasch- 

 karoff s (1914a) "Vergleichendes Studium der Or- 

 ganisation von Plectognathi." This was evidently to be 

 the first of a series of anatomical monographs concerned 

 with "Materialen zur Vergleichenden Morphologie der 

 Fische," but, just as with Rosen, something in those 

 troubled times was to cut short the series. Kaschkaroff 

 was not aware of Rosen's work until after completing his 

 own studies, for he said at the close of his paper that it 



The only outstanding peculiarity of the above was the 

 close association of Orthagoriscus (= Mola) with Triodon, 

 but there was no explanation in the text as to the reasoning 

 that lead to this association. Kaschkaroff went on to say, 

 however, that HoUard's classification was acceptable, 

 and the latter was presented by Kaschkaroff (1914a:360) 

 with the statement that "die alte Klassifikation von 

 Hollard erscheint mir vollkommen begrundet." 



Kaschkaroff discussed what "Der Vorfahr" of the Plec- 

 tognathi should be, listing the characteristics of this 

 hypothetical ancestor. The list (1914a:359) added up, in 

 essence, to a triacanthoid with a large amount of carti- 

 lage in its skeleton. He did not believe that the plectog- 

 naths arose from an acanthurid stock, for the latter did 



