DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 199 



First dorsal (composed of about 2(t spines) coDtiuuous, extending to the second; fiiilets 

 behind tlie dorsal and anal; a dagjiiH-shaped spine behind the vent. No keel on the tail. 

 Caudal flu well developed. Veutrals reduced to a spine each. Seven branchiostegals. 



NEALOTUS TRIPES, JonxsoN. 



Nealotus tr'qtes, Johnson, Proc. Zool. Soc, Lond., 18G5, 4;M.— Gi-ntiier, Cli;illenger Kfi>()rt, xxii, 1887, 35. 



Body very elongate, with a few large, deciduous, simple scales of delicate structure 

 here and there upon its surface. 



The height of the body is contained 9A times iu its length; the length of the head -ih 

 times. Head flattened above, concave in the interorbital region, with four low ridges, the 

 inner pair of which inclose an elongate, diamond-shaped space; lower jaw longest. 



Eye round, lateral, its diameter ecpial to one-tifth of the length of the head; length of 

 the snout is 1§ times the diameter of the eye; opercle with two obtuse projections behind, 

 separated by a notch. 



Spinous dorsal inserted in front of the root of the i>ectoral, its height slightly greater 

 than half that of the body; its length less than half that of the body; placed in a groove, 

 supported by twenty-one simi>le slender spines; the second dorsal is placed close behind the 

 first, not so high and less than half as long, with nineteen rays, and followed l)y two tirdets. 



The pectoral origin is under the angle of the opercle ; its length is equal to that of the 

 second dorsal tin. The spines representing the ventrals are inserted close together under 

 the hinder part of the roots of the pectorals; their length about one-fourth of the height of 

 the body. These spines are longitudinally grooved, and each appears to consist of two or 

 three spines coalesced together. 



Vent very slightly postiredian; a flat, dagger-shaped spine, longitudinally grooved, 

 half as long as the height of the body, inserted close behind the vent. The anal fin is 

 inserted behind this spine at a distance about equal to its length, and is opposite to, but 

 rather shorter than the second dorsal. Caudal fin deeply furcate. 



The lateral line descends obli(piely from above the opercle to the middle of the length 

 of the flsh, and then continues with a gentler obliquity along the posterior part of the 

 body to the tail, where it is inserted at one-third of the distance from the ventral to the 

 dorsal outline. 



Eadial formula: D. XXI | 19 | ii; A. 18 | Iii; 1'. 1.!; V. 1. 



This species closely resembles Promeihichthijn alhoiticiis, from which it may be dis- 

 tinguished by the dagger-shaped spine in front of the anal fln, by the greater number of 

 spines in the first dorsal — iil instead of 18 — by the smaller number in the second dorsal — 

 19 instead of 21 — and by the longer anal, which has 18 instead of 10 spines. It also has 

 the ventral spines under the posterior angle of the pectorals, instead <>f in advance of 

 them, and has its lateral line descending more gently. 



From Nesiarchns it is distinguished by its ventrid tins and by the absence of the car- 

 tilaginous x>rolongations of the jaws. 



"This fish," remarks Giinther, " was known fVon,\ a single example, 10 inches long, 

 obtained at ^Madeira iu the month of December, and lias been fully (h^scribed by .Johnson. 

 The ChaUcnijer collection contains a very young specimen, only .{3 millimeters long, which 

 agrees so well with Johnson's description that it no doubt belongs to the same species. Only 

 the dagger-shaped postanal spine is shorter than the ventral spines, and also the seiiaration 

 of distinct finlets can not be clearly made out, as miglit be expected in so young an exam- 

 ple. It was brought up in the dredge at Cltallciu/er station 10, in lat. 3-to 51' N., Ion. ()8o 

 30' W., where the dredge had reached a depth of 2,r.7r. fathoms. However, no part of the 

 organization of these Trichiuroids indicates that they descend to so great a de])lh, whilst, 

 on the other hand, young Trichiuroids are not rarely found near the surface. It is, there- 

 fore, nmch more probable that this small fish entered the dredge shortly before it came to 

 the surface." {Giinther.) 



