FISHES OF HAWAIIAN ISLANDS. 
505 
Body uniform brownish; head of deeper shade; a very narrow black border along the dorsal and 
upper lobe of caudal. 
Known only from the type, said to have been taken at the Hawaiian Islands. 
Congrogadus marginatus Vaillant & Sauvage, Rev. Mag. Zool., Ill, 282, 1875, Sandwich Islands. 
Family XCVIII. FIERASFER I DtE. — Pearl Fishes. 
Body elongate, compressed, tapering into a long and slender tail; no scales; teeth cardiform on 
jaws, vomer, and palatines; canine teeth often present; no barbels; lower jaw included; vent at the 
throat; gill-membranes somewhat united, free from the isthmus; no pseudobranchiae; no pyloric coeca; 
vertical tins very low, confluent, without spines; no ventral fins; pectoral fins present or absent. Small 
shore fishes of tropical seas, often living in shells of mollusks, echinoderms, etc., being especially often 
commensal with the pearl oyster and with the larger Holothuria. 
Genus 252. FIERASFER Cuvier. 
Gill-membranes little connected, leaving the isthmus bare; no distinct caudal fin; pectoral fins 
developed. A genus with few poorly defined species, only one of which is known from Hawaiian 
waters. 
Fierasfer Cuvier, Rfegne Anim., Ed. 1, II, 239, 1817 ( imberbe=acus ). 
Echiodon Thompson, Proc. Zool. Soc. Lond. 1837, 55 (drummondi) . 
Diaphasia Lowe, Proc. Zool. Soc. Lond. 1843, 92 ( acus ).. 
Oxybeles Richardson, Voy. Erebus and Terror, Fishes, 74, 1844-48 (homei), 
Porobronchus Kaup, Ann. Mag. Nat. Hist. 1860, 272 (larva of Fierasfer acus). 
Carapus Gill, Proc. Ac. Nat. Sci. Phila. 1864, 152 (after Rafinesque, 1810). 
Vexittifer Gasco, Bull. Assoc. Nat. Med. Napoli 1870, 59 (larva of Fierasfer acus). 
Lefroyia Jones, Zoologist, IX, 1874, 3838 (bermudensis) . 
423. Fierasfer umbratilis Jordan & Evermann. Plate 61. « 
Head 10.2 in length; depth 15.2; eye 5 in head; snout 4.8; mouth 2.6; interorbital 4.5. 
Body very elongate, compressed; tail very long and tapering gradually in a long point; head 
elongate, conic, its depth 2 in length, width 2.25; snout rather broad, conic, and produced beyond 
mandible; mandible broad, flattened below; mouth nearly horizontal, broad, the gape reaching below 
posterior margin of eye; premaxillary teeth minute, confined to anterior half of jaw, apparently in a 
single series. The mandibular and palatine teeth seem also in a single series, those on side of mandi- 
ble directed laterally toward angle of mouth, none of them enlarged ; 2 or .3 vomerine teeth, the largest 
in the mouth, and arranged in a longitudinal series. Eye rather small, anterior, without eyelid, and 
placed about first quarter of head; nostrils well separated, anterior with elevated rim, posterior a short, 
crescent-like slit; interorbital space rather broad, convex; gill-opening low, inferior, rather long; gill- 
membrane free from isthmus, its angle nearly an eye diameter distant from posterior margin of eye; 
dorsal fin almost rudimentary, very low and thin; anal rather broad, in middle its height about 0.75 
in eye, from which point it gradually decreases to tip of tail, where it is rudimentary, like dorsal; tail 
ending in a fleshy point, caudal fin apparently absent; pectoral small but relatively large, 3.1 in head, 
rays very minute; lateral line distinct, running down along middle of side on posterior half of tail; 
no scales. 
Color when fresh (field No. 03506), pale olivaceous, with pale greenish spots; a pale bluish streak 
in each spot over lateral line; pale purplish oblong spots on lower half of body; head greenish-olive, 
with pale green spots closely set on cheek and jaw; pale purplish dots on upper part of cheek and 
behind eye; first dorsal same as body, but the spots yellowish; a black spot behind first and second 
rays, tips pale; rays of second dorsal checked alternately with yellowish-green and white; caudal same 
as second dorsal, but margin yellowish; anal yellowish olive, tip blackish; pectoral and ventrals pale; 
iris greenish-yellow; dull red streaks radiating from pupil. 
Color in alcohol brown; head and end of tail dark sooty or blackish brown, the color formed of 
dark points; greater part of anal fin, lower surface of body anteriorly and pectoral and branchiostegal 
membranes pale straw color; lower surface of trunk more or less blotched with pale brown. 
a Jordanicus umbratilus on plate. 
