230 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



TETRAGONURUS, Risso. 



Tetfagonurus, Risso, Ichth. Nice, 1810, 347; Hist. Nat., in, 381.— GOnther, loe. cit.— Moreau, Hist. Nat. 

 I'oiss. France, m, 178. 



Body subcylindrical, elongate. Snout obtuse. Ventrals abdominal, placed below 

 middle of pectoral. 



TETRAGONURUS CUVIERI, Risso. (Figure 417.) 



Corvus niloticxs, Aldrovandi, De Piscibus, v, cap. 25, 28. 



Tetragonurus Cuvieri, Risso, Ichth. Nice, 1810,347; Hist. Nat. Eur. Merid., 1829, in, 381. 



Tetragonurus atlantious, Lowe, Fishes Madeira, 129, pi. xix. 



Spinous dorsal low, receivable in groove. Scales each with 5 to G keels, each termi- 

 nating in a spine. Color, brown, with violet and yellow reflections. 



Radial formula: D. xv-xxi, 1, 11-13; A. 10-12; L. lat. US/20. 



This form was originally described from Nice. Risso says that it lives at great depths, 

 approaching the coast only in August at the time of spawning, and that its natation is 

 slow and feeble. It has since been found off Toulon and Marseilles, and by Lowe near 

 Madeira, where it was taken swimming at the surface. Lowe is also of the opinion that it 

 occurs at very great depths. Its flesh when eaten is a violent poison, as was demonstrated 

 by the personal experience of Risso himself. A single specimen was obtained by the U. S. 

 Fish Commission at Wood's Holl, Massachusetts, November 10, 1890 (Cat .No. 41436, U. S. 

 N. M.). 



Family CHILODIPTERID^E. 



Chilodipteroidei, Sleeker, Tentamen, 1859, xx. 

 Chilodipterida, Gii.l, Arrangement, Families of Fishes, 1872. 

 Apogonina, GCnther, Cat. Fish. Brit. Mas., I, 1859, 57, 222. 

 Apogonidie, Jordan A Gilbert, Bull, xvi, U. S. Nat. Mas., 1883, 563. 



Percoidea, with body oblong, more or less elevated, covered with large deciduous scales 

 (striated and ctenoid, or sometimes cycloid); cheeks scaly; cleft of mouth wide, oblique. 

 Villiform teeth on jaws and vomer, and sometimes on palatines (teeth absent in Brepho- 

 8toma); canines sometimes present; preopereulum commonly with a double ridge; its edge 

 entire or slightly serrated; lower pharyngeals separate, with sharp teeth; pseudobranchias 

 present; brauchiostegals 7, or less; dorsal fins well separated, the first with 6 to 9 rather 

 strong spines; anal flu short, with 1 to 3 (usually with 2) spines; ventral fins thoracic, I, 5. 



KEY TO THE DEEP-SEA GENERA OF CHILODIPTERID.E. 

 (Provisional — including some genera of doubtful relationship.) 



I. Canine teeth at the outer side of the villiform bands in the jaws. 



A. Preopereulum with a double serrated edge; aual with two spines. 



1. Dorsal with six spines ; operculum unarmed (C'niLoniPTERts) 



2. Dorsal with nine spines; operculum with two weak spines Parascombrops 



II. Teeth all villiform; no canines. 



A. Lateral line normal. 



1. Palatiues with teeth. 



a. Anal with two spines. 



Preopereulum with double serrated ridge (Apogon i 



Preopereulum with double entire ridge. 



Scales large, 20-20 in lateral line (APOGONICHTHYS) 



Scales small, 40 or more in lateral line Glossamia 



b. Anal with three spines; bones of head cavernous. 



Preopereulum denticulated; operculum with two feeble points. 



Scabs small, 45 in lateral line Malacichthys 



2. Palatines toothless. 



a. Preopereulum with striated angle. Teeth moderate. B. vn EpiGONCS 



b. Preopereulum with oue spine. Teeth rudimentary on jaws. "B. IV" PoMATOMICHTHYS 



B. Lateral line beginning under origin of second dorsal. 



1. Anal with two spines Microichthys 



