700 PLECTOGNATHI. 



remarked that due to their poisonous nature they are even objected to as mannrein Malayan countries. In Egypt 

 exists a poisonous Tetrodon, wliilst at the Cape of Good Hope eating a spotted Tetrodon has caused so many 

 deaths amongt the sailors in harbour, that they are specially warned against employing them as food. 



The colours of these fishes are subject to considerable variation: thus (as in T. stellatus), abdominal 

 bands may be seen in the young (T. lineatus), but absent or only slightly marked in the adult : but the young 

 also may be destitute of these bauds. Spots may be present or absent, as in a variety of T. nitjropunctat us 

 there are no spots. 



The extent of the spines may vary in the same species of the fish, thus in T. nigro2}unctatus some 

 examples may be almost entirely covered with well marked spines, or such may almost be concealed in the 

 skin, or even be nearly absent. 



Geographical distribution. — Tropical and sub-tropical seas entei-ing estuaries, whilst some few are found 

 in fresh waters. 



SYNOPSIS OP INDIAN SPECIES. 



A. — Bade broad: nasal organs conspicuous. 



a. — Tiro nasal openings on either side, situated in a single and prominent papilla (Tetraodon, Bleaker). 



1. A fold of skin along the loiver part of the side of the tail {Gastrophysns, MiiUer). 



1. Tetrodon inermis. Very soft spines on the abdominal surface only, and not extending to vent. A 

 dull band from eye to tail, above this plumbaceous, below silvery white. Seas of India to Japan. 



2. Tetrodon lunaris. Spines along the back to the dorsal fin, and along the abdomen. Silvery. 



3. Tetrodon saeleratus. Spines along the back to the dorsal fin, also along the abdomen. Greenish 

 superiorly, with brown spots : a triangular white spot before the eye. Red Sea to the Malay Archipelgo, and 

 beyond. 



4. Tetrodmi hi/psehgenion. Spines of moderate size, rather wide asunder, going from eye to dorsal fin, 

 along abdominal surface to vent, and also behind pectoral fin. Yellowish brown, with light or white spots on 

 the back, and white on the sides and below : from 3 to 6 vertical bands below the eye : caudal barred. Red Sea 

 to Australia. 



5. Tetrodon oUongus. Two-rooted spines from nostrils to dorsal fin : a few on cheeks, and numerous on 

 abdomen as far as vent. Brown bands from back down the white sides : round or oval white spots on head 

 and back. Seas of India to China, and beyond. 



h. — A fringed but single, imperforated, nasal cavity with a fringed edge : hodij spiny. 



6. Tetrodmi patoca. Three or 4-rooted spines from nostril to dorsal fin, interiorly to the vent. Brown 

 superiorly with many round or oval white sjjots. Seas of India to China. 



c. — A simple and circular nasal cavity : body spiyieless {Monotretus, Bibron). 



7. Tetrodon cutcutia. A light interorbital band : a black ocellus on the side anterior to the dorsal fin : 

 reticulated all over : caudal fin tipped with carmine. Fresh waters of Orissa, Bengal and Assam. 



(7. — Tico solid tentacles, one on each side of an impervious nasal fossa {Arothron, Miiller). 



8. Tetrodon immaculatus. Small sjiines cover the body, except snout and posterior half of the tail : 

 interorbital space broad Without spots or lines : or with parallel lines on the body, or spots on the head. 

 Red Sea to the Malay Archipelago, and beyond. 



9. Tttrodon nigropunctatws. Spines small, usually covering the entire body ; interorbital space narrow. 

 Brownish, more or less covered with black spots : vent in a black spot. Red Sea to the Malay Archipelago, 

 and beyond. 



10. Tetrodon stellatus. Spines small, covering the body. Brownish, with dark spots placed closely 

 together on the back and u]iper portion of the sides : vent in a black spot : the young with black semi-circular 

 abdominal bands. Red Sea to the Malay Archipelago, and beyond. 



11. Tetrodon reticularis. Spines small, covering the body. Body superiorly gray or browm, becoming 

 white below : with concave black bands which are continued round the eye : white spots on back : caudal 

 reticulated with black. Seas of India to the Mahiy Archipelago and New Guinea. 



12. Tetrodon his2ndus. Spines small, those on abdomen with 2 or 3 roots, they cover the body to the base 

 of the caudal fin. Brown along the back with bluish- white spots, and one or two light bands round the orbit 

 and also round the base of the pectoral fin. Sometimes lines or spots of black on the abdomen, but not 

 ascending on to the cheeks. Red Sea to the Malay Archipelago, and beyond. 



13. Tetrodon leopardus. Two-rooted and widely separated spines from eye to dorsal fin, also along the 

 abdominal surface to the vent : dark along , the back with round white spots : a light interorbital band : 

 I'eticulated black lines enclosing spaces on the dorsal and caudal fins. Seas of India. 



14. Tetrodon viridipunctatus. Two-rooted and widely separated spines from eyes nearly to doraal fin, and 

 inferiorly as far as anus. Back dark green, with emerald green spots : a light interorbital band vrith a central 



