Equatorial forms(^) These exhibit various degrees of restriction to the equatorial zone. Two examples
(Fig. 10.7) show mild and extreme restriction.
(^) Euphausia diomediae: Euphausiid
(^) Eucalanus subcrassus: Copepod
Fig. 10.7 Pacific distributions of (a) Eucalanus subcrassus, an equatorial belt copepod
(^) (after Lang 1965),
and (b) Euphausia diomediae, a tropical euphausiid
(after Brinton 1962).