n.WlDSON — SCOTTISH UAi;i!ONU''Klt(tlJS DRACIIIOI'ODA. 
2G9 
10 — 17. rroiluctns unclatiis. Two oxainplos, from tlio same locality and col- 
lection of Mr. Young. 
18. scabriculus, Martin. From the Campsie main limestone. The 
interior of the dorsal valve will be found represented in )jl. v. 
19. ■ puatulosus, Phillips. North of Glasgow (?) ; collection of the 
Geological Survey. The same thing may be repeated hero that we 
have said under fig. 14. 
20. fimctatns, Martin. From near Lesmahago. One part shows 
the spiny investment, of which 20c and il are enlarged illu.strations. 
21. — . Internal cast of the ventral valve seen from the 
beak, and showing the relative position of the occlusor (A) to the 
divaricator (R) muscular impressions. 
22. . Interior of the dorsal valve ; collection of Mr. 
Armstrong. 
23. spinulosus. Sow. From the original example in the collection 
of Dr. Fleming. 
24. . From near Lesmahago ; collection of Dr. Slimon. 
25. costatus, var. muricatus, PhilUps. From Cessnock, near Gal- 
ston. This specimen agrees exactly wdth the original example so 
named in the museum of York, and which has been considered a syno- 
nym of P. costatus. 
26. ■ — latissinnts, J. Sow. Interior of the ventral valve. From West 
Broadstone, Beith ; in the collection of Mr. Armstrong. 
Plate V. 
1. Frodnctus rjiganteiis, Martin. Bi'aidwood Gill, Lanarkshire. Tliis 
species attains more than twice the dimensions of the figure. 
2. ■ . Interior of the ventral valve. A, occlusor ; E, di- 
vaiicator impi-essions ; L, hollows occupied by the oral arms. 
3. . Interior of the dorsal valve. A, occlusor ; J, car- 
dinal process ; X, renifoi'm impressions ; Z, prominences correspond- 
ing with the hollows (L) in the opposite valve. 
4. . Hinge-hne showing the upper surface of the car- 
dinal process, J. 
5. cora. A portion of the external sm-face magnified to show its 
peculiarly sculptured striae. Coirie Burn ; collection of Mr. Young. 
6. ■ scabriculus. Interior of the dorsal valve, from two Lanarkshire 
specimens : the partially divided mesial ridge and cardinal process 
are peculiar. From the collections of Mr. J. Armstrong and that of 
another friend. 
7. Youngianus, Dav. This figure shows the concentric lines of 
growth, which had not been sufficiently expressed upon the figures 
ah'eady given. 
8. Spiriferina Jaminosa, M'Coy. From Lammerton ; in the collection of 
Mr. G. Tate. This is only a cast, the shell being destroyed. 
9. . A fragment of the shell magnified to show the dis- 
position of the laminee which adorn the sm-face. 
10. Spirifera hisulcata. A remarkably elongated variety, in the Hunterian 
Museum, Glasgow College. A similar specimen has been found near 
Lesmahago. 
11. trigonalis (?). Campsie; formerly in the collection of Mr. 
A. Cowan, now in that of the Geological Society of Glasgow. I am 
somewhat uncertain whether this shell, of wliich many similar ex- 
amples have been found, is in reality a variety of Sp. trigonalis or of 
Sp. duplicicosta. 
12 — 13 — 14. Cra/nia quadrata, M'Coy. From Capel Eig and Calderside ; in 
the collection of Messrs. Thomson and J. Armstrong. 
