264 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



find none." Bleeker admits three genera, Ostracion, Aracana, and Cew- 

 taurus, the hitter tbnuded on a grotesque form known to ichthyologists 

 only from a drawing of a very young individual made by Dr. Hooker. 

 Ostracion is divided by Bleeker into subgenera as follows : 



OstracioH, Art. z^ Tctrosomu>i, Swii8. z= Rhincffomus, Swn.s. = Latophrijs, Swns. 

 = Cibotion, Kp. 



Pyxis postice iutegrii basiu piiniiii dorsalis et aualis inclucleus, medio iufeiue jilana 

 nou carinata. Piuna dorsalis. Pinna caadalis radiis 10 (1 | 8 | 1). Si^ec. typ. Ostra- 

 cion ietratjonns, L. 

 Subgenus Ostracion, Art. Pyxis tetragona, trigona \i'l pentagoua, anacautlia. Spec. 



typ. Ostracion tetra{jonus,'Tj. 

 Subgenus Latophrifs, Swns. Pyxis trigona vel peutagona, utroque latere carina ven- 



trali postice spina armata. Sp. typ. Ostracion trigonus, L. 

 Subgenus Tetrosomus, Swns. Pyxis trigona vel peutagona orbitis, crista dorsali me- 



diaua carinisque ventralibus acantbopliora, spiuis orbitalibus sursum ucc antrorsum 



directis, ventralibus plurib us. Spec. typ. Ostracion turriius, Forsk. 

 Subgenus Acanthostracion, Blki'. Pyxis trigona, peutagona, a'cI tetragona orbita ca- 



riuaque ventrali postice acantbopliora, .si)inis orbitalibus antrorsum directis. Spec. 



typ. Ostracion qiiadricornis, L.* 



These divisions correspond very closely to those of Lac6pede already 

 referred to; Ostracion being equivalent to section 1, Lcefophrys to section 

 3, while section 4 is about equally divided between Tetrosomus and 

 Amnthostracion . 



Dr. Giinther,t like Hollard and Bleeker, considers the typical Ostra- 

 cions to be embraced within the limits of one natural genus, and even 

 includes those with carapace open behind the anal tin. Such, at least, is 

 his course in the generic diagnosis of Ostracion^ though he actually 

 adopts the name Aracana as if it represented a true genus, and enumer- 

 ates the species under a separate series of numbers. 



In arranging the si^ecies of Ostracion he adheres rather to the method 

 of Swainson than of Lacepede, considering the shape of the carapace to 

 be the most convenient basis of classification. His divisions are as fol- 

 lows : 



I. Carapace three ridged. 

 II. Carapace foiu- or five ridged, without si^iues. 

 III. Carapace four ridged Avith spines. 



The third division corresponds exactly to Swainson's Tetrosomus, if 

 his diagnosis be accepted without change, the second division to Swain- 

 son's Ostraciow and Kaup's Cibotion, the first division to the three last 

 subgenera (!) of Swainson, which he probably meant to subordinate to 

 a third genus which he neglected to name. 



The usage of American authors has been various. Storer, although 

 he described his Holmes' Hole specimen under the name Ostracion Yalei, 

 accepted in his '^Synopsis" the mimes Rhinesonms triqueter and Lacto- 

 phrys sexcornis. 



* Atlas ichthyologique, v, 180.5, pp. 27-28. 



t Catalogue of the Fislies in the British Museum, viii, 1870, p. 256. 



