the plectognaths and Lophius and the placement of all of 

 these with the elasmobranchs and cyclostomes were ma- 

 jor differences in the treatment of the plectognaths by 

 Artedi and Klein. Klein's Crayracion and Capriscus are 

 more or less synonymous with, respectively, Artedi's 

 Ostracion and Batistes. Both of Artedi's groups con- 

 tained only plectognaths (except for Macrorham- 

 phosus). but the same cannot be said of Klein's. The lat- 

 ter described 32 species of Crayracion, of which most are 

 ostraciids, tetraodontids, diodontids, or molids, but 

 species 7 (p. 19) and 11 (p. 19) are Cyclopterus and 

 species 32 (p. 23) is a syngnathid. On the other hand, all 

 11 species of Klein's Capriscus are balistoids. 



In his "Museum Ichthyologicum," Gronovius (1754) 

 followed precisely the classification adopted by Artedi, 

 with Pisces containing the Plagiuri, Malacopterygii, 

 Acanthopterygii, Branchiostegi, and Chondropterygii. 

 The Branchiostegi again contained four types: Balistes, 

 Ostracion, Cyclopterus, and Lophius. Gronovius made 

 no innovations in the Balistes category; on the contrary, 

 one of his species of Balistes appears to be Marcgrave's 

 antenneriid frogfish from Brazil. However, Gronovius did 

 go a step beyond Artedi in his handling of the Ostracion 

 group. Gronovius divided his Ostracion into three sub- 

 groups on the basis of body shape, thus: Corpore quad- 

 rangulo, with three ostraciids; Corpore triangutato, with 

 three more ostraciids; and Corpore cathetoplateo, uel 

 rotundo. with two tetraodontids and a molid. Although 

 Gronovius' (1763) subsequent "Zoophylacium" is post- 

 Linnaean chronologically, it is pre-Linnaean in its ter- 

 minology. His Pisces were now divided into Plagiuri, 

 Chondropterygii, Branchiostegi, and Branchiales, the 

 latter group being roughly equivalent to his previously 

 used Malacopterygii and Acanthopterygii. Within these 

 groups the species were segregated according to fin struc- 

 ture. Thus, his Branchiostegi were arranged as follows: 



Pinnis Ventralibus nullis: Muraena, Gymnotus, Syn- 



gnathus, Ostracion. 

 Pinnis Ventralibus spuriis: Balistes, Cyclopterus, 



Cyclogaster. 

 Pinnis Ventralibus veris praesentibus: Gonorynchus, 



Cobitis, Uranoscopus, Lophius. 



New groups were added to the Artedian Branchio- 

 stegi, and, beyond that, Gronovius (1763) added a fur- 

 ther subdivision to the Ostracion category. The Balistes 

 category remained a simple descriptive list of a number 

 of balistoids and a macrorhamphosid. The four Ostracion 

 subgroups that Gronovius recognized were: Corpore 

 quadrangulo, with four ostraciids; Corpore triangulato, 

 with three more ostraciids; Sphaerico, uel oblongo- 

 rotundo corpore, with two diodontids and one tetraodon- 

 tid; Corpore cathetoplateo, with two tetraodontids and 

 two molids. When comparison is made between the 

 classification of the nonbalistoid plectognaths of 

 Gronovius and that of Linnaeus, it is obvious that 

 Gronovius simply incorporated into his Ostracion sub- 

 groups a few of Linnaeus' ideas without an excess of 

 ■recision. 



With the 10th edition of Linnaeus' (1758) "Systema 

 Naturae," a basic division of the plectognaths into four 

 genera (Balistes, Ostracion, Tetraodon, Diodon) was 

 presented for the first time. Five groups of Pisces were 

 recognized by Linnaeus: Apodes, Jugulares, Thoracici, 

 Abdominales, and Branchiostegi. The latter contained 

 the following genera: Mormyrus, Balistes, Ostracion, 

 Tetraodon, Diodon, Centriscus, Syngnathus, and 

 Pegasus. 



But to the above Pisces must be added the fishes which 

 Linnaeus placed in the Amphibia Nantes, containing 

 Petromyzon, Raja, Squalus, Chimaera. Lophius, and 

 Acipenser. 



Such a classification shows an eclectic approach to the 

 systems of previous workers. The Branchiostegi of Artedi 

 is a much smaller group than that of Linnaeus, and the 

 only species that are common to the Branchiostegi of 

 both are the plectognaths. Thus, Cyclopterus and 

 Lophius appeared in Artedi's Branchiostegi, but Lin- 

 naeus placed Cyclopterus in the Thoracici and Lophius 

 in the Amphibia Nantes. Mormyrus, Centriscus, Syn- 

 gnathus, and Pegasus of the Linnaean Branchiostegi are 

 found among the Acanthopterygii and Malacopterygii of 

 Artedi. In short, as far as the plectognaths are con- 

 cerned, Linnaeus (1758) had followed Artedi's views, 

 only adding generic names to the four plectognath sub- 

 groups that Artedi had at least implicitly recognized. 

 The Linnaean Balistes contained seven balistoids and a 

 macrorhamphosid; Ostracion, nine ostraciids; Tetraodon 

 (spelled Tetrodon on p. 243 in the list of genera of 

 Branchiostegi but Tetraodon on p. 332 where defined), 

 five tetraodontids and one molid; Diodon, seven diodon- 

 tids. Linnaeus thus recognized 29 plectognath species, 

 only two more than Artedi had recognized 20 years 

 previously. Many of Klein's 43 species of Crayracion and 

 Capriscus were synonymized by Linnaeus, or dis- 

 regarded as unrecognizable. 



In the 12th edition of Linnaeus' (1766) "Systema 

 Naturae" a major change took place in the classification 

 of the plectognaths — Branchiostegi was eliminated. All 

 of the genera of the former Branchiostegi were placed in 

 the Amphibia Nantes, except for Mormyrus, which was 

 placed in the Abdominales. The Amphibia Nantes then 

 consisted of an odd assortment of types: Petromyzon, 

 Raja, Squalus, Chimaera, Lophius, Balistes, Ostracion, 

 Tetrodon, Diodon, Cyclopterus, Centriscus, Syng- 

 nathus, Acipenser, and Pegasus. The motive behind the 

 placement of the plectognaths in the Amphibia Nantes 

 was the erroneous report sent to Linnaeus by Dr. Gar- 

 den, a physician in Charleston, S.C, who informed Lin- 

 naeus that Diodon possessed a lung. A combination of 

 three anatomical peculiarities in Diodon probably led to 

 the confusion, for Diodon not only has a distensible 

 diverticulum of the oesophagus that can be filled with 

 either air or water (at the time of Linnaeus it was thought 

 to undergo inflation only by the intake of air), but the 

 swim bladder is bilobed anteriorly and the well- 

 developed kidneys are placed far forward. Linnaeus 

 wrote (1766:348) that "Garden in America habitant!, 

 petere, vellet dissecare Diodontis respirationis organa & 



