328 ANACANTHINI. 



Second Group— Fierasferina. 

 Ventrals absent: vent near the throat. 



Genus II — Fierasfer, Cuvier. 



Fchiodon, Thompson. Diaphasia, Lowe. Oxybeles, Richardson. Porobronchus, 

 Kaup (young). 



Branchiostegals seven : pseudobranchios absent. Body ending in a long and 

 tapering tail. Gill-openings wide, the membranes united beneath the throat but not 

 attached to the isthmus. Gills four. The upper jaw overlapping the lower. No 

 barbels. Gardiform teeth on the jaws, vomer, and palatine bones, while canines may 

 likewise be present. Vertical fins continuous; ventrals absent. Vent placed under 

 the throat, Scales, if present, minute. Air-bladder present. Pyloric appendages 

 absent. 



Kaup described (Ann. Mag. 1860, vi, p. 272, pi. iii, f . D.) the young of Fierasfer 

 acus as the type of a new genus, Porobronchus, destitute of pectoral fins. 



Some of these fishes seem to be endowed with peculiar habits or those of 

 a " free messmate " seeking its fortune inside the trepang, Holothuria, within its 

 digestive canal, or its arborescent respiratory processes which open at the posterior 

 extremity of the body. Dr. Greef, at Madeira, found one residing within a trepang : 

 while Quoy and Gaimard also observed a species inside Stichopus tuberculosus. 

 Professor Emery, of Naples, has also remarked upon how this fish, when in the 

 tanks in the Aquarium, works itself into a Holothuria, going in tail foremost as if 

 to be able to readily emerge when appropriate food were present near the outlet. 



Geographical distribution. — Cosmopolitan in temperate and tropical seas. 



1. Fierasfer dentatus, Plate XCI, fig. 2. 



Fierasfer dentatus, Cuv. Regne Anim. ; Kaup, Apodal Fish, p. 158 ; Yarrell, 

 Brit. Fish. (Ed. 3) i, p. 82, c. fig. ; Gunther, Catal. iv, p. 383 ; Emery, Faun. Nap. 



Fchiodon Drummondii, Thompson, Proc. Zool. Soc. 1837, p. 55, Trans. Zool. 

 Soc. ii, p. 207, pi. xxxviii, and Nat. Hist, Ireland, iv, p. 231 ; Yarrell, Brit, Fishes 

 (Ed. 2) ii, p. 417 ; Bonap. Pise. Eur. p. 41 ; White, Catal. Brit. Fish. p. 51 ; Giglioli, 

 Pesc. Ital. p. 37. 



Drummond's echiodon, Couch, Fish. Brit. Isles, iii, p. 133, pi. clvi. 



B. vii, D. 180, P. 16, A. 180, C. 12, Vert. 98. 



Length of head 9^, height of body 14 in the total. Fye — diameters 4-J in the 

 length of the head, 1 diameter from the end of the snout, and 1 apart. Width of 

 the head equal to 2/7 of its length : several rows of open pores on its surface. 

 Nostrils large, situated just in front of the centre of the eye. Mouth obliquely 

 cleft. Teeth — cardiform, in the upper jaw anteriorly two (or rarely one) pairs of 

 canines : in the lower jaw one or sometimes two pairs, the differences in numbers 

 being frequently due to one or more teeth having been broken off. Fins — the 

 dorsal commences slightly in advance of the base of the pectoral fin, its rays 

 highest posteriorly. Central caudal rays the longest. Fin rays articulated, but 

 none branched. Vent below the base of the pectoral fin. Scales— apparently 

 absent. Lateral-line — consisting of a depression extending along the whole length 

 of the side, anteriorly above, and posteriorly in the middle of its depth. Colours 

 ■ — reddish, with the sides dotted, and the outer edges of the fins blackish. 



Habits. — Of these but little are known. 



Habitat. — South coast of Ireland, Mediterranean to the Italian shores. 



Thompson, in June, 1836, obtained one 11 inches long, which was found dead 

 on the beach at Carnlough, near Glenarm, in the county of Antrim, after a strong 

 easterly wind. A second example, 8 inches in length, was found on the shore of 

 the harbour of Valencia, county of Kerry, about February, 1852. 



The figure is from Thompson's original illustration. 



