The mouth, farther back, between the maxillipeds.
"A Guide for the Study of Animals" by Worrallo Whitney
In the young Lobster, when just hatched from the egg, however, each of the legs has a large exopodite like that of the third maxilliped.
"The Life of Crustacea" by William Thomas Calman
The maxillipeds increase in size from first to third pair.
"Elementary Zoology, Second Edition" by Vernon L. Kellogg