Hermit crab crab has several long spines, a long, narrow abdomen, and large fringed antennae. Several zoeal moults are followed by the final larval stage, the megalopa. Hermit crabs are often seen as a "throwaway pet" that would live only a few months, but species such as "Coenobita clypeatus" have a 23-year lifespan if properly treated, and some have lived longer than 32 years. Hermit crabs are more closely related to squat lobsters and porcelain crabs than they are to true crabs (Brachyura). However, the relationship of king crabs to the rest of Paguroidea is a highly contentious topic. Many studies based
On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection paper, consisting of the letter and papers, was published in the "Zoological Journal of the Linnean Society 3" (20 August): 46–50. The paper consisted of a communication letter by Joseph Dalton Hooker and Charles Lyell dated 30 June 1859, giving information on the three sections of the papers. The introduction is shown below, along with the section headings: MY DEAR SIR,—The accompanying papers, which we have the honour of communicating to the Linnean Society, and which all related to the same subject, viz. the Laws which affect the Production of Varieties, Races, and Species, contain the results of the investigations