PISCES. 163 
Helodus pusillus (McCoy). Polyrhizodus pusillus, F. McCoy, A. 
M. N. H. ser. 2, 11 (1848), p. 126 and Contrib. Brit. Pal. (1854), 
p. 21, and Brit. Palzoz. Foss. (1855), pl. 11 k, f. 2, 2.4, 8, 
p. 642. Carboniferous Limestone ; Armagh.  ['Tooth.] 
H. rudis, v. Psephodus magnus. 
Holoptychius giganteus, Agassiz. H. princeps, F. McCoy, A. 
M. N. H. ser. 2, m1 (1848), p. 310, and Contrib. Brit. Pal. 
(1854), p. 42, and Brit. Palseoz. Foss. (1855), p. 595. Old Red 
Sandstone ; Scat Craig. [Scale.] 
H. hopkinsi, v. Acrolepis hopkins. 
H. princeps, v. Holoptychius giganteus. 
H. sedqwicki, v. Glyptolepis leptopterus. 
Homacanthus macrodus, F. McCoy, A. M. N. H. ser. 2, I 
(1848), p. 115, and Contrib. Brit. Pal. (1854), p. 10, and Brit. 
Palzoz. Foss. (1855), pl. ui kK, f. 20, 20 a, p. 632. J. W. Davis, 
Trans. Roy. Dublin Soc. ser. 2, 1 (1883), p. 362 (not figured). 
Carboniferous Limestone; Armagh. [Spine.] 
H. microdus, F. McCoy, A. M. N. H. ser. 2, 11 (1848), p. 115, and 
Contrib. Brit. Pal. (1855), p. 10, and Brit. Palzeoz. Foss. (1855), 
pl. ui K, f. 19, 19 a, p. 633. Carboniferous Limestone; Armagh. 
[Spine.] This specimen cannot be found. 
Ischyodus brevirostris, v. 1. thurmanni, 
Ischyodus thurmanni, Pictet and Campiche. J. brevirostris, 
Egerton, var. 2, E. T. Newton, Chimeroid Fishes Brit. Cret. 
Rocks (Mem. Geol. Survey, 1878), pl. ix, f 11, p. 31. Lower 
Chalk; Isleham, near Newmarket. {Right mandibular ramus. ] 
Janassa clavata (McCoy). Chomatodus clavatus, F. McCoy, 
Brit; Paleoz. Foss. -(1855),. pl--ur K;'f, 10,10) a, 6; sp. °6 LT. 
Carboniferous Limestone; Armagh.  ['Tooth.] 
Chomatodus (Petalodus) truncatus, Agassiz, F. McCoy, ibid. 
(1855), pl. i 1, f. 1, L a, p. 618. Carboniferous Limestone ; 
Armagh. [Tooth.] 
J. imbricata (McCoy). Climawxodus imbricatus, F. McCoy, A. M. 
N. H. ser. 2, 11 (1848), p. 129, and Contrib. Brit. Pal. (1854), 
p. 24, and Brit. Palaeoz. Foss. (1855), pl. 11 G, f. 5, 5 a, p. 620. 
Carboniferous Limestone ; Derbyshire.  ['Tooth.] 
112 
