Compare the capital "G" in Glasgow with capital at the start of the maiden name of the mother. Although there's a small tail coming down beneath the line, I see that as the final wee flourish when the registrar finishes off his capital "C", so my vote goes for a surname starting "Cob..." and the only one that I can think of that matches is "Coburn". The reason for some remaining doubt in my mind is that the registrar has slurred the "rn" a bit ....
Look also at the wife's name, and that of the 3rd child, - Cordellia for other examples of the "C" ........and to really confuse matters look at the "C" in Catherine, - the informant
The 5 children shown match +/- 1 year the extracted records for the parents on IGI, except that 1 Janet may be "missing", and what happened to Malcolm and Catherine ??, - surely his sister knew about the most recent family members, and I'll take some convincing that there were two INNES families in the same area at the same time where the wife was Cordel[l]ia McLean
(Parents married Barony 08Dec1833.)
JANET INNES - International Genealogical Index
Gender: Female Birth: 10 OCT 1834 Greenock Par, , Renfrew, Scotland
JANET INNES - International Genealogical Index
Gender: Female Christening: 05 NOV 1836 West Or Old Parish, Greenock, Renfrew, Scotland
AGNES INNES - International Genealogical Index
Gender: Female Christening: 10 APR 1836 West Or Old Parish, Greenock, Renfrew, Scotland
[something not quite right here with the second Janet and Agnes dates, but note that these are christenings, not births.]
CORDELIA INNES - International Genealogical Index
Gender: Female Christening: 31 AUG 1838 West Or Old Parish, Greenock, Renfrew, Scotland
WILLIAM INNES - International Genealogical Index
Gender: Male Christening: 29 AUG 1840 West Or Old Parish, Greenock, Renfrew, Scotland
NEIL INNES - International Genealogical Index
Gender: Male Christening: 07 OCT 1842 West Or Old Parish, Greenock, Renfrew, Scotland
MALCOLM BUCHANAN INNES - International Genealogical Index
Gender: Male Christening: 29 DEC 1844 West Or Old Parish, Greenock, Renfrew, Scotland
CATHERINE INNES - International Genealogical Index
Gender: Female Christening: 10 JAN 1846 West Or Old Parish, Greenock, Renfrew, Scotland
David