Pisces. | DEVONIAN VERTEBRATA. 595 
HoLoprycHIUs NOBILISSIMUS (Ag.) 
Ref—Ag. in Murch. Sil. Syst. t. 2 bis, fig. 1; Ag. Old Red, t. 23. 
Desc.—Length rather more than two feet, with a thickness of about ten inches; scales of the body thick, 
about one and half inches wide; exposed part about a fourth wider than long; posterior margin elliptical ; 
surface with irregular, very coarse, slightly waving, interrupted, longitudinal ridges and furrows, the latter 
deeply pitted, and the former obscurely nodular, giving a coarse reticulated character to the surface. 
As Sir R. Murchison states this to be named after its discoverer, the Rey. J. Noble, would it not be well 
to change the spelling of the specific name to Woblei ? 
Position and Locality —Old Red sandstone, Clashbennie. 
HoLoprycuHius PRINCEPS (A7°Coy). 
Ref.—M Coy, Ann. Nat. Hist. 2nd Series, Vol. II.; Sil. Syst. t. 2 bis, fig. 3. 
Desc.—Scales subquadrate, slightly convex, each about three inches wide, and two and half inches long ; 
anterior concealed margin widest, convex ; posterior exposed portion about one-third narrower, subtruncate, 
rounded, sides slightly concave; whole of the exposed surface closely covered with irregular tubercles, about 
half a line in diameter, and half their diameter apart; most of the tubercles are a little elongated, but in 
irregular directions, and towards the anterior margin a few of them are generally confluent at their bases, 
forming short, irregularly twisted, strongly tuberculated ridges; concealed anterior portion and interval between 
the tubercles minutely porous. 
This species far exceeds the H. nobilissimus (Ag.) or H. giganteus (Ag.) in size ; it is easily distinguished 
by its entirely tuberculated surface. A fragment of this species is well figured (without a name) in Murchison’s 
“ Silurian System,” pl. 2 bis, fig. 3, and as H. giganteus in t. 36 of his “ Siluria.” 
Position and Locality—Old Red conglomerate of Scat Craig. 
Hotorprycuius SepGwIickit (M*Coy). PI. 2. D. fig. 6. 
Ref—M ‘Coy, Ann. Nat. Hist. 2nd Series, Vol. II. 
Desc.—Body fusiform, very thick, depth in the middle one-third of the length, abruptly narrowed towards 
the tail, the pedicle of which, at the base of the anal and dorsal fins, is scarcely half the depth of the body ; 
head more than one-fourth of the length ; tail very short, nearly square, the thick, articulated, frequently 
branched, rays developed from the under side, forming a broad triangular caudal fin, obliquely truncated on its 
posterior margin; dorsal rather larger than the opposite anal fin ; both semielliptical, twice as high as long ; 
the anal about one-third the length of its base in advance of the caudal; ventral fins broad; their length 
about equalling their height, rather more than the length of their bases in advance of the anal fin; lateral 
line nearly medial, strongly marked. Scales thin, rounded; those of the flanks half an inch in diameter, 
subtrigonal, posterior margin semicircular, concealed anterior margin very broad, subtruncate, with very minute, 
radiating punctate striz; a small space towards the middle of the scale is covered with a distinct granulation 
(frequently but not always seen when the scales are in sitw) ; all posterior to this, or the constantly exposed 
portion, covered with a minute, longitudinal, irregularly flexuous, striate punctation, intermixed with numerous 
sharp, narrow, irregularly interrupted, longitudinal, thread-like ridges, of very irregular number and length, but 
usually two or three times their diameter apart ; the exposed part of the scales of the flanks, when in sitw, 
is about one-third higher than long. Teeth conical, one-third longer than wide, half the diameter of their 
bases apart. Length eleven inches, depth nearly four inches; length of teeth three-fourths of a line. 
This species, like the H. Flemingi (Ag.), is remarkable for being found on its side, indicating apparently 
a compressed, instead of a depressed form; it also resembles that species in the sculpturing of the scales, but 
