1862.] OF FISHES FROM MADEIRA. 173 



Anal, distance from tip of mandible, mouth open . . 6A 



, height in front l|^ 



Caudal, length 1^ 



Tail, height behind second dorsal -^^ 



Order ACANTHOPTERYGII, Cuv. 



Fam. Trichixjrid^. 



Nesiarchus, gen. nov. 



Body elongate, covered with small scales. Cleft of mouth deep. 

 Several strong teeth in the jaws ; none on the palatine bones or the 

 vomer. First dorsal not extending to the second. No finlets behind 

 either the dorsal or anal fin. Perfect thoracic ventral fins present. 

 Caudal fin well developed. A dagger-shaped spine behind the vent. 

 No keel on the tail. One lateral line. Seven branchiostegal rays. 

 An air-bladder. Pyloric cseca in moderate number. 



This genus may be entered in the Synopsis of Trichiuroid genera, 

 given in the Cat. of the Brit. Mus. Collection, thus : — 



" Ventrals present : a dagger-shaped spine behind the vent." 



Nesiarchus nasutus, sp. n. (PI. XXII.) 



1st D. 20. 2ndD. 2. 21. A. 22. P. 13. V. 1.4. C. vii. 8-i-7. 

 vii. M. B. 7. 



This fish has much of the external aspect of Thyrsites prometheus. 

 The body is very elongate, compressed, covered with small, deciduous, 

 cycloid scales, which are elegantly marked with concentric striae ; 

 the height of the body, compared with the total length, is as 1 to 

 13. The head is scaly in every part, but unarmed ; it is compressed, 

 and the cheeks are flat. There is a broad groove between the eyes 

 and on the snout, as in Aphanopus. The length of the head, com- 

 pared with the total length, is as 1 to 4|. The round eye is placed 

 at the side of the head, and does not quite reach to the outline ; it 

 is contained 9^ times in the head, is rather more than a diameter 

 distant from the other eye, and each is distant about A\ diameters 

 from the tip of the snout. The members of each pair of nostrils are 

 distant from each other, and the hinder one is a small oblique slit. 

 The bones of the scaly opercle and subopercle are thin and radiato- 

 striate ; the border of the former has an angular projection. The 

 gill-openings are wide. The snout is long, and is terminated by a 

 large conical cartilaginous process, which projects much beyond the 

 jaw. The mandible has a similar but longer cartilaginous process. 

 These processes (some rudiments of which may be seen in Aphano- 

 pus) bestow on the head somewhat of the appearance of Sphyrcena 

 vulgaris. The rictus is large. The upper border of the mouth is 

 formed entirely of the premaxillary, which is broad above and narrow 

 below. The scaly maxillary, which lies exposed behind, and is broad 

 below and narrow above, does not quite reach back to the vertical 

 from the middle of the eye. The mandibular bones project a little 

 beyond those of the upper jaw. 



