580 BRITISH PALAXOZOIC FOSSILS. [ Pisces. 
Genus. CHIROLEPIS* (Ay.) 
Gen. Char.—General form of body, elongate, ovate ; one dorsal fin, a little behind the line of the anal fin ; 
anal resembling the dorsal ; ventrals small, half-way between the pectorals and anal; pectorals large, slightly 
pointed ; all the fins destitute of the bony spinous ray usual in the family, each having the anterior edge set 
with fulcral scales instead. 
The mouth is nearly horizontal, and its margin is formed, according to Agassiz, of the maxillary bone; who 
also has had an opportunity of noting that the large and small teeth are in one row, and not the latter forming 
a continuous row outside the others, as in the Sauroidea and Ceelacanthi. 
The fin-rays of this genus are always better preserved than those of the allied Acanthodes or Chiracanthus. 
The Genus is named from the very fine articulated fin-rays, having a deceptive resemblance to the scales 
of the body. 
CHIROLEPIS cuRTUS (M‘Coy). PI. 2. D. fig. 1. 
Ref —MCoy, Ann. Nat. Hist. 2nd Series, Vol. II. 
Desc.—Short, fusiform, mouth very oblique; head very large, nearly one-third the entire length of the 
fish ; body rapidly tapering from the head to the tail, which is very small, and with a shallow concave posterior 
margin ; fins small, ventrals nearly three times longer than high, reaching to the anus, where the anal begins ; 
the anal is about twice the height of the ventral fins, and not quite so long, rather less than its own length 
in advance of the caudal; the dorsal is slightly less in all directions than the anal, and is about one-third of 
its length behind it ; scales rhomboidal, four in the space of one line, each with a long, prominent, oval tubercle 
in the middle, parallel with the posterior margin (some of those on the tail are diagonally sulcated in the 
direction of the length of the fish). 
In the form and position of its fins this much resembles the C. Cummingice (Ag.), from which it differs 
in its larger head, more oblique mouth, smaller tail, and much shorter and more rapidly tapering body and 
tuberculated scales; by the latter character it approaches the C. Traillii (Ag.), from which it differs in the 
position of its fins, and equally with the C. Cwmmingie (Ag.) in the other characters mentioned above. 
Length seven and half inches, greatest depth of body one and half inch, Fulcral scales broad, oval, two 
lines long and three-fourths of a line wide. 
Position and Locality—Rare in the Old Red sandstone nodules of Lethen Bar. 
Explanation of Figures.—Plate 2. D. fig. 1. Natural size; 1 a, scale from near the tail, outer surface 
magnified twenty-four diameters; 1 4, scale, impression of inner surface, from near the middle of the fish, 
shewing a prominent oval boss in the middle arising from a corresponding articular depression in the scale; 
magnified twenty-four diameters. 
CHIROLEPIS MACROCEPHALUS (M‘Coy). Pl. 2. D. fig. 3. 
Ref—MCoy, Ann. Nat. Hist. 2nd Series, Vol. II. 
Desc.—Body thick, fusiform ; tail short, abruptly narrowed from behind the anal fin to half the depth 
of the body at the pectorals; head very large, nearly one-third the entire length; teeth nearly equal, conical, 
pointed, width of the base two-thirds of the height, their bases nearly in contact; pectoral fins narrow, oval ; 
yentrals nearly central, of moderate size, half their length distant from the anal, which is triangular, its height 
two-thirds its length, although less than haif the depth of the body at its base; the dorsal is only two-thirds 
the length of the anal, but its height slightly exceeds its length; its anterior extremity is vertically over the 
middle of the anal fin, the posterior extremity extending slightly behind the extremity of the anal; caudal very 
large, deeply forked, but the upper lobe twice the length of the lower; fulcral scales very slender, about 
* Spelt Cheirolepis, by Agassiz. 
