The relationship between the common and scientific (often erroneously called latin) names of Gulls contain much confusion and obfuscation which is at the heart of the matter.
First in my medley of confusion (as seen in the header image) is Croicocephalus ridibunus, commonly known as Black-headed Gull whose scientific name actually translates as ‘Laughing Gull’. Unfortunately for those keen on accuracy it has a chocolate brown head and then it occurs only in the adults when in breeding plumage. The rest of the year its head is mainly white.
The titular gull of this site is the Gull whose common name actually does mean ridibundus - the Laughing Gull Leucophaeus atricilla. For no reason that I can discern it has a scientific name that seems to translate as ‘sea crow’. It doesn’t look much like a crow to be fair but for the record adults do have a black head. Once again this only occurs in breeding plumage and the rest of the year it is mainly white.
Thirdly we have Larus melanocephalus which literally has the scientific name that the first bird’s common name denotes, (Black-headed Gull) and it really does have a black head but (you know where this is going) only in adults in breeding plumage and the rest of the year it is mainly white (albeit with a natty bandit mask). Due to a previous geographical loyalty this gull has the common name Mediterranean Gull. They are not confined to the Mediterranean any more. The UK winter hotspot for what will be referred to a lot in this site as ‘Meds’ is in Great Yarmouth and the birds are more than likely German or Polish. Oh, yes.
To further illustrate the initial point that I made, it is worth pointing out that the Common Gull is not that common, the White-eyed Gull doesn’t actually have white eyes, the Herring Gull rarely eats herring, the Iceland Gull isn’t restricted to Iceland and the Yellow-legged Gull does not have yellow legs for the first few years of its life. And just because it looks like a Yellow-legged Gull doesn't mean that it is a Yellow-legged Gull.
To counter all of this confusing nomenclature, I should note that the Little Gull is relatively quite small and its specific name (minutus) reflects this.
And that, in a nutshell, explains very little or very much.
For what it’s worth, I’ve never seen a Laughing Gull.