382 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Habitat. — Both coasts of tropical America. 
Etymology. — Furcifer, one who carries a fork, from the form of the tail. 
We have examined numerous specimens of this species from Cuba, Cape San Lucas, 
and the Galapagos Islands. We are unable to distinguish the Pacific coast form 
(colonus) from the Atlantic 
The skeleton of the species has been described in detail by Dr. Gunther (I, 101). 
Genus XW— HYPOPLECTRUS. 
Plectropoma species Cuvier &. Valenciennes (not type). 
Hypoplectrus Gill, Proc. Ac. Nat. Sci. Phila., 1862, 236 (puella). 
Type. — Plectropoma puella Ouv. & Val. 
Etymology. — 'Dro, below; irk^xTpov, spur. 
The species of this genus agree very closely with the type of Serranus, Prionodes, 
etc., differing chiefly in the form of the body, which is more deep and compressed 
than in the other groups allied to Serranus. The skull differs from that of Prionodes 
chiefly in the development of the occipital crest, which, in accordance with the form 
of the body, is much elevated. All the species have several autrorse serrae on the 
lower limb of the preopercle, much as in Plectropoma, Acantliistius, and related genera, 
but smaller than in any of these. The species have been usually placed in Plectro- 
poma, but, except the aualogous armature of the preopercle, we know of no natural 
character which would tend to show any special affinity between Plectropoma and 
Hypoplectrus. In the form of the body there is, however, some resemblance between 
Hypoplectrus and Gonioplectrus. 
The species* of Hypoplectrus are all American, and a study of their relations offers 
many difficulties. 
We have examined typical examples of a large number of the nominal species. 
While each of these shows certain striking peculiarities in color, most of them are abso- 
lutely identical in other respects. Moreover, even among those in which the colora- 
tion seems most sharply defined there are many variations. After an examination 
of the large series of typical forms sent by Professor Poey to the museum at Cam- 
bridge, we find ourselves driven to the conclusion that nearly all the forms of Hypo- 
plectrus constitute but a single species, subject to almost endless variations in color. 
This view we here adopt, leaving for convenience’ sake the various nominal species to 
stand as color varieties, produced by the action of some agencies as yet unknown. 
AI^ALYSIS OF THE SPECIES OF HYPOPLECTKUS. 
a. Scales large, 6-46-13 ; body short and deep, the depth 2^ in length ; head 2f ; profile from dorsal to 
occiput convex, concave above eye; preorbital narrow; maxillary reach- 
ing to below middle of eye; lower jaw slightly included ; teeth strong, 
large teeth in front fourth dorsal spine highest, 2^ in head; middle 
caudal rays little shorter than the outer ones; pectoral reaching anal; 
teeth of preopercle growing larger downwards ; angle and lower limb 
with ahouii nine strong radiating serrse ; those nearest the angle largest, 
the others directed more and more forwards. Color (of the single speci- 
men known), black with violet luster ; faint, pale streaks along the rows 
of scales on lower parts of body ; caudal fin abruptly translucent yellow- 
ish ; pectorals colorless ; tips of dorsal and anal spines and edge of soft 
rays abruptly whitish Lamprurus, 63. 
