Hello,
The right ref is CK 615 with a 26.5 inside. Here is a catalog page displaying it (the same as in Gatorcpa'post I assume) :
One of mine says hello :
The database may be right also as it refers to the CK 615 23.4SC, i.e. the same case design but with a different caliber inside. The reference number at this period was referring to the case design and you could have several variations (for example XX-26.5, XX-23.4, XX-24.4SC, even XX-30 later).
Indeed there has been a CK 615 23.4 SC, here in a 1940 catalog :
Unfortunately I don't own one of those....
CK 615 isn't the scarab and, AFAIK, doesn't have a nickname.
The ref CK 2009 shown by JiminOz (Hi Jim!) is a different ref with a different design - just compare the lugs - and is the one called 'small scarab'.
Here in a 1940 catalog :
One of mine says hello :
The 'Scarab' is a ref 2014, same shape but larger (easy to differentiate from CK 2009 as it has a crown that is intergrated in the bezel).
Here in a 1937 Italian catalog :
One of mine says hello :
