78 ACANTHOPTERYGII. 



Family, VIII TRACHINIDiE, Risso. 



Branchiostegals from five to seven : pseudobranchiae present. Body more or 

 less elongated, posteriorly compressed. Eyes more or less lateral. Cleft of 

 mouth almost horizontal, lateral, or even nearly vertical. Some of the bones of 

 the head are usually armed : the suborbital ring of bones does not articulate with 

 the preopercle. Teeth in the jaws small and pointed, present or absent on the 

 vomer and palatines. One or two dorsal fins, the rays being generally con- 

 siderably more in number than the spines : anal similar to soft dorsal : no finlets. 

 Ventrals thoracic with one spine and five rays. Pectorals with or without 

 appendages. Body scaled or scaleless. Air-bladder present or absent. Pyloric 

 appendages few. 



Geographical distribution. Cosmopolitan, rarely of large size. The majority 

 are littoral forms, some entering freshwaters or rivers, while a few are present 

 among coral reefs. Although in some Genera, as Sillago, these fishes are rather 

 rapid in their movements, the majority included in this family are the reverse, 

 some being very inactive. 



Genus I Trachinus, Cuvier. 



Branchiostegals six : pseudobranchioz present. Body elongated and cylindrical, 

 with the cleft of the mouth very oblique. Eyes lateral, directed somewhat upwards 

 and outwards. Preorbital and preopercle serrated : opercle with a strong spine. 

 Villiform teeth in the javjs, on the vomer and palatine bones, none on the tongue. 

 Two dorsal fins, the first with five to seven spines : second dorsal and anal many rayed. 

 Ventrals jugular. The lower pectoral rays unbranched. Scales cycloid and very 

 small. Air-bladder absent. Pyloric appendages few. 



The term Trachinus has been referred to several Greek derivations, but the 

 most simple is that it is a latinized corruption of dracoena (dpuxaiva) which is still 

 its Greek name, as well as signifying a dragon or serpent ; while its likewise 

 being called araneus, or a "spider" by the Latins also had reference to the 

 poisonous character of the wounds it inflicts. Two species frequent the British 

 coasts, the larger Trachinus draco, the smaller Trachinus vipera, the latter being 

 the more venomous. Ancients asserted that so dreaded were they even by their 

 finny neighbours that all gave place to the weever. Opinions have been much 

 divided respecting the seat of the virus or poison ; some, as Rutty, asserting that 

 such resided in "the fin near the neck which has five prickles which are the seat 

 of what is called its venom." Others have limited the poisoned wounds to such 

 as are inflicted by the opercular spines. But it has been shown* that both the 

 double grooved opercular spines and also those of the first dorsal fin are poison 

 organs, the latter of which besides being grooved, contains a cavity within the 

 substance of the spine where the poison would seem to be deposited prior to its 

 use, while means by which such could be ejected have not yet been discovered. 

 No specific poison-gland has been found, but it has been surmised that the virus 

 is a secretion or excretion from the mucous surface of the loose skin which covers 

 the spines, or its pulpy sheath, this substance would collect in the grooves, and 

 when penetrating a foreign body sufficiently deep would naturally be introduced 

 into the inflicted wound. Even the death of the fish does not appear to at once 

 arrest its virulence, as pricks from the spines of dead weevers have been observed 

 to occasion symptoms of poisoning. f 



* Byerly, Proc. Liverpool Lit. and Phil. Soc. i, p. 156. 



t On the poisonous nature of wounds caused by these fishes, see Schmidt, Nord. Med. Ark. vi, 

 No. 2, 1875. 



