PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 277 



=Teuthyini, Bonaparte, Nuovi Annali delle Sci. Nat., t. 2, p. 130, 1838 ; t. 4, p. 190, 1840. 

 =Teuthyini, Bonaparte, Cat. Metod. dei Pesci Euxopei, p. 7, 1846. (2. S. F. of Teu- 



thyidsB.) 

 =TentMm.'B, Gill, Cat. Fishes E. Coast N. A., p. 34, 1861. 



Teuthidoidea with the abdominal (vertebral) portion much shorter 

 than the caudal; the rayed portions of the dorsal and anal equal and 

 much exceeding the spinous ; the ventrals with an external spine and 

 with three to five rays ; the head with its rostral portion produced and 

 long, and with epipleurals developed from the ribs. 



The neural spine of the last abdominal vertebra (in the nine-spined 

 'species) is in advance of the interneural spine, whose head is behind 

 and embraces the base of the recumbent last dorsal spine. 



SYNOPSIS OF GENERA. 



I. Caudal armature developed as immovable laminae. 



1. Ventrals with 5 rays each ; anal with 3 spines ; caudal plates, typically, 4 



to 6 Prionurus (1). 



2. Ventrals with 3 rays each ; anal with 2 spines ; caudal plates typically 



2 (rarely 1 or 3) Monoceros (2). 



II. Caudal armature developed as movable antrorse spines, erectile from and de- 



pressible in grooves. 



1. Ventrals with 5 rays. 



a^. Teeth fixed and strong. 



fti. Dorsal spines 9 (rarely 7 or 8) '. Teuthis (3). 



y^. Dorsal spines 3 to 5 Zebrasoma (4). 



a*. Teeth movable and setiform, but with dilated apices ; 



(D. 8) Ctenoch^tus (5). 



2. Ventrals with 3 rays Colocopus (6). 



DIAGNOSES OF GENERA. 



1. Prionurus. 



Synonymy. 



= Prionurus Lac^pbde, Ann. Mus. d'Hist. Nat., t. 4, p. 205. 

 = Prionurus Cuvier, R^gne Animal, 2. ed., t. 2, p. 224,1829. 

 = Prionurus Giiniher, Cat. Fishes Brit. Mus., v. 3, p. 347, 1861. 

 Acanthnrus sp. Langdoi-ff. 

 Naseus sp. BleeTcer, olim. 



Teuthidids with many (4 to 6) pairs of fixed carinated caudal plates, 

 5-rayed ventrals, and 3 anal spines. 

 Type. — P. microlepidotus^ Lac. 



2. Monoceros. 

 Synonymy. 



y> Monoaevoa, Bloch, Syst. Ich., Schneid. ed., p. 180, 1801. 



> Naso, Lac^p^dc, Hist. Nat. des Poissons, t. 3, p. 106, 1802. 



> Nasonus, Eafinesque, Analyse de la Nature, p. — , 1815. 



