270 GVMNODOXTES. 



short, truncate. Vertical fins confluent. No j^elv'ic hone. Air 

 bladder ahscnt. 

 .Taws without median suture 10. OrtJiaf/oriscu.s, p. 317. 



First Group. TRIODONTINA. 

 1. TEIODON. 



Triodon, (lieinwardt) Ci<v. JRer/ne Anim. 



The upper jaw divided by a median suture, the lower simple. 

 Body covered with small osseous, scale-like, spiny subimbricate 

 laminae. Two distinct nasal opeuings on each side. Tail long, ter- 

 minating in a distinct bilobed fin ; Caudal and anal fins short. 

 Abdomen dilatable into a very large, compressed, pendant sac, the 

 lower part of which is merely a flap of skin, into which the air does 

 not penetrate. The sac is kept expanded by the very long pelvic 

 bone. Skeleton ossified, with the ribs well-developed. 



Indian Ocean and archipelago. 



1. Triodon bursarius. 



lietiard, Foiss. Moll. ii. pi. 30. fig. 142 ; Ru.i/sch, Anib. p. 31, pi. 16. 



fig. 1. 

 Triodon bursarius, (Remio. ) Cuv. Regne An. ; Blcek. Verh. Bat. Gen. 



xxiv. Bluotk. p. 20, and Atl. Ichth. Gyimiod. p. 84, pi. 10. fig. 1. 

 macropterus, Less. Voy. Coqu. Zool. pi. 4 ; Dareste, Ann. Sc. 



Nat. xii. p. 68, pi. 1. fig. 1 (osteol.). 



B. 6. D. 10. A. 9. C. 18. 



Eye large, about one-fourth of the length of the head. A largo 

 irregidar black spot edged with yellow on the upper part of the ven- 

 tral sac. 



Indian Ocean and archipelago. 



a-h. Adult (19-21 inches long) : stuffed. Mauritius. Purchased 



of Mr. Cuming. 

 c-d. Adult : stuffed. India. 



Second Group. TETRODONTINA. 



Globe-fishes, well known from their being able to fill their body 

 with air, and to float on the surface of the water belly upwards. 



2. XENOPTEEUS. 



Xenopterus, Bihron, Rev. Zool. 185-5, p. 281. 



Chonerhinus, Bleek. Atl. Ichth. Gyvinod. p. 77 (not before charac- 

 terized). 

 Jaws divided by a median suture. Body with small dermal ossi- 

 fications, each with two or three roots and a spine. Dorsal and anal 

 fins many-rayed. Nostrils funnel-shaped, with fringed margin. 

 Indian archipelago. 



