105 



As I always place the smallest forms with the most rounded skull 

 at the head, and give the bird-types whh the largest pectorals, which 

 enable these forms to fly, the second place, and as I see in the 

 Peristethus the bone- or reptile-fish, and in Prionotus the real fish- 

 type, my arrangement of the genera in this little subfamily is as 

 follows : — 



I. Cephalacanthus. 

 II. Dactyloptera. 



III. Peristethus. 



IV. Prionotlts. 

 V. Trigla. 



After this preface, we proceed to distinguish the different species of 



Genus III. Peristethus (Peristedion*). 



Peristethus cataphractus. (PI. VIII. fig. 1.) 



Peristedion cataphractum, Lac. 



P. cataphractum {S) et chahrontera ( $ ), Risso, iii. p. 402. 

 Octonus holosteon, Raf. 

 Trigla hispanorum chahrontera, Osb. 

 Trigla hamata, Bl. Schu. 



Malarmat, Rond. p. 237 {6), excellent fig. ; Cuvier & Val. iv. 

 p. 101 {6), excellent fig. 



Peristedion malamart, Yarr. p. 67 {S), excellent fig. 



This figure of Bloch, t. 49 (6), is bad, shows too many scales 

 and rays in the second dorsal. 



Biagn. — Front with three thorns. Eye-covers with thorns. Pre- 

 opercle leaf-shaped, without prolongation. The length of the 

 head to the breadth under the middle of the eyes as 2^ : 1 . 

 Breadth of the head nearly equal to its height, measured under the 

 eyes. The forks more or less divergent. 



Not exceeding the length of a foot. Common in the Mediter- 

 ranean, more rare in the Channel. 



Peristethus orientalis. (PI. VIII. fig. 2.) 



Peristedion orientale, T. & Schleg. Fn. Jap. t. xiv. f. 5, 6 ; t. xv. 

 f. 1, 2. 



Similar in length to P. cataphractus, but without thorns on the 

 front, and eye-covering. A female, besides the short rays of the first 

 dorsal, shows the ventral shield separated into two, which is abnor- 

 mal. On the symphysis are three small skin prolongations, and 

 behind it a longer one. 



I find the true specific character in the form of the head, and 

 therefore doubt whether the number of the rays shows a great dif- 

 ference from the other species. 



* The name Peristedion is wi'ongly formed. 



