A posterior saccular aneurysm may not be so obvious.
2
In the majority of the Decapoda there is a saccular invagination of the integument in the basal segment of the antennular peduncle having on its inner surface " auditory " setae of the type just described.
3
The gonads, as in other Arthropoda, are hollow saccular organs, the cavity communicating with the efferent ducts.