256 
In his monograph Gru vel (1905, p. 19) says: „Écailles des 
rangées supérieures aplaties, de couleur gris sombre, petites, en 
séries circulaires serrées et réguliéres; sur tout le reste du pédon- 
cule, les écailles prennent la forme d’épines irréguliérement dis- 
posées“. In spite of the great number of adult animals of the 
typical Mitella polymerus from La Jolla, it has been impossible to 
confirm these statements. A doser study without exception reveals 
the regularly alternating arrangement of the scales all over the 
peduncle, and no trace of „spines“ was found. In typical specimens 
the scales (Fig. 16) are always broad and rounded, viewed from the 
a b c 
Fig. 17. Mitella polymerus f. ecliinata from San Pedro, Calif. Gapitulum of adult 
specimen in a lateral, b rostral, and c carinal aspect. [X 2]. 
flat side. Nevertheless the animal itself in every detail coincides 
with the descriptions given by previous authors. I have, therefore, 
given the name of forma typica to the common La Jolla specimens. 
The material also contains some specimens of a Mitella which 
at first sight might be considered as another species (Fig. 17). The 
plates of the capitulum are more siender, and pointed; the inter¬ 
vals, especially between the upper latera, therefore become more 
conspicuous, and the regular serial arrangement of the plates is 
less obvious. In smaller specimens these differences from the forma 
typica are very pronounced; in a larger specimen, on the other 
hånd, the differences are somewhat less obvious. Most different is 
the armature of the peduncle. In the specimens here referred to, 
the scales of the peduncle (Fig. 18 c) are siender, and jut out from 
