302 
SELACnil. 
P. 3831.' Type spocimon of JJyhodus dorsalis, Agassiz, described and 
figured, tom. cit. p. 42, pi. x. fig. 1 ; Stoucsfield Slate, 
Stonesficld. Ennislcillen Coil- 
's. 2159. The fragmentary extremities of two similar spines ; Stoncs- 
field. Eijerton Coll. 
47148. Portion of a nearly similar spine, more curved, with larger 
posterior denticles ; Great Oolite, Blisworth, Northamp- 
tonshire. Sharp Coll. 
P. 2904. Type specimen of Ilylodus maryhialis, Agassiz, described 
and figured, tom. cit. p. 43, pi. x. fig. 18; Stonesfiold 
Slate, Stonesfield '. Enniskillen Coll. 
P. 490. Smaller fragment assigned to II. maryinalis, Agassiz, tom. 
cit. pi. X. figs. 19, 20; Stonesfield. Eyerton Coll. 
P. 2832. Portion of still smaller spino, labelled “ Ilyhodus maryin- 
alis, Agass.,” in Agassiz’s handwriting ; Stonesfield. 
Enniskillen Coll. 
47146-7. T wo imperfect abraded stout spines, larger than the 
foregoing ; Great Oolite, Orton, near Peterborough. 
Sharp Coll. 
P. 2161. Extremely abraded but less incomplete example of the 
same spine ; Groat Oolite, Stonesfield Eyerton Coll. 
47143. Worn extremity of an equally large and stout spino; Great 
■ Oolite, Wcodon, Buckinghamshire. Sharp Coll. 
V. Kimmeridge Clay. (a) Dorsal Fin-spines. 
P. 489. Typo specimen of Ilyhodus acutus, Agassiz, described and 
figured, tom. cit. p. 45, pi. x. figs. 4-0 Lower Kim- 
meridgo Clay, Shotover, near Oxford. Eyerton Coll. 
P. 2157. Two fragments of nearly similar spines, the larger speci- 
men showing the posterior dent icles more clearlj" separated 
into two longitudinal series than in the type ; Lower Kim- 
mcridge Clay,Kimmeridge Bay, Dorsetshire. Eyerton Coll. 
’ A fragment from the Upper Corallian of Hanover is al.so assigned to this 
species by K. Fricke, Pnlcconlogr. vol. xxii. (187.')), p. 3!)0, pi. xxii. lig. 5. See 
also C. Struckmann, Wcalcleubild, Umgegend Hannover (1880), p. 01, pi. ii'- 
fig- L „ 
“ Dorsal fin-spines from Stonesfield are also figured under the names oi 
H. dorsalis, H. apkalis, and H, marginatus, by J. I'liillips, Geol. Oxford, p. 178, 
diagr. xxxviii. figs. 1, 2, 6. 
A fragment from the Upper Corallian of Hanover is also assigned to this 
species by K. Fricke, Palmontogr. vol. xxii, (1875), p. 300, pi. xxii. fig. 0- 
