We examined the value of using cytological criteria for sponge taxonomy within the well-
defined genus Polymastia and redescribe the species Polymastia janeirensis comb. nov.
Comparison of the anatomical, morphological, and skeletal characteristics of P. janeirensis
with those of the 17 other known Atlantic species demonstrated that P. janeirensis is closely
related to P. agglutinans and P. mammillaris. The study confirmed that the close relationship
between P. janeirensis and P. mammillaris can also be recognized at the cytological level …

Printed in Canada/Imprimé au Canada strated that in most cases the organization of the
choanocyte chambers is typical of the sponge order or family (Boury-Esnault et al. 1984;
Vacelet et al. 1989; Boury-Esnault et al. 1990; Langenbruch 1991). Although Topsent as
early as 1900 (p. 45) strongly emphasized the necessity of describing cell components in
species diagnosis, Simpson (1968) was the first to demonstrate the usefulness of cellular
composition in taxonomy. Special mesohyl cells such as glycocytes, spherulous cells …