Those are definatly Lemon Sharks. But its sad they are being sold and especially in a 1,500 gallon system. First off Lemons grow to large for 99.9% of aquarists to house ethical. They need systems of atleast 30,000, how do people figure 1,500 will do justice? If they have an email please supply with me with, or go in there your self and tell them about the Shark and recommend they donate them to a Local Aquarium and never get them in again. They could put Grey Smoothhounds perfectly in that tank for life, no need to threaten 3 Lemons with theirs. As for the "dwarf" hammerhead, it is indeed a Bonnet Head Shark, Bonnets are in the "Hammerhead" family, they share the same physical descriptions. Bonnets need around 4,000 gallons to be house ethical and enjoyable. And shouldn't be attempted by anyone other than a professional or someone who has been involved with Shark husbandry and keeping for many years. Again, the stores email would be helpful.