486 Cc. A. NILSSON-CANTELL 
were placed together, two were very typical and the middle one more aber- 
rant. In the shape of the capztu/um these aberrant individuals showed some 
resemblance to the variety ¢estudinata, as stated by comparison with the type 
material. This is also evident from the figures of BORRADAILE (1916, fig. 6) 
of L. affinis, which is synonymous with var. ¢estudinata (NILSSON-CANTELL, 
1928). 
It was of-interest to compare these individuals with specimens collected 
by Cand. phil. S. ERLANDSSON, Upsala, from wood in Bohuslan, Sweden, 
where the species is a rare guest. The latter specimens are in my opinion inter- 
mediate between the two types mentioned here. The limits between these 
smaller variations are not very distinct. Owing to our very insufficient know- 
ledge of the forms of this species it seems wise not to split it up in too many 
varieties. Certainly the specimens from Masatierra represent no local race, 
for I have seen the same type from different parts of the world in museum 
collections. A comparative study of the material of Lefas anatifera in various 
museums would certainly clear up many of the variations in this species. 
As I was able to compare my material with the specimens collected by 
Dr. PLATE in Cumberland Bay, Masatierra (described by WELTNER, 1895), I 
can state that the former is identical with that in the Berlin Museum. Thus 
number 8991 consists of a very typical form with a long carina. The individual 
studied is of the same shape as shown in fig. 1a—d. The other specimen I 
have seen viz. number 8992 in the Berlin Museum is quite like those with a 
shorter carina with less developed branches (fig. 1 e—z). It appears that 
WELTNER did not observe this difference as he does not say anything about 
that. I still think he is right in regarding them all as L. anatifera. 
A description of the different characters of the aberrant specimens may 
be given. The scuta have no umbonal teeth in these individuals (fig. 1 f), as is 
also the case with var. /estudinata. In the specimens from Bohuslan referred 
to above, one has a distinct umbonal tooth on the right scutum, the other has 
teeth on both scuta. 
The z¢ergum has the dorsal corner less pointed than in the other more 
typical individuals. The occludent part of the plate is more projected and 
placed in a straight line with the occludent margin of the scutum, a feature 
which is typical for var. zestudzinata. 
The carina in these individuals is broader and shorter than in the typical 
specimens — a character of no great importance. Also the fork is different 
from the first mentioned with the prongs more or Jess developed as seen from 
the fig. 1 g—z. Between these prongs is a small median prominence in some 
specimens. BORRADAILE gives this as typical for L. affinis. As we have 
seen here, this is a variable character. In the specimen from Bohuslan, which 
must be regarded as rather typical, this little prominence is also developed. 
As a curiosity it may be mentioned that one specimen was very deformed 
this being certainly caused by its position on the floating object. The right 
scutum is well developed and convex so that the whole capitulum is bent over 
to the other side. The carina is also bent over in the upper part to this side. 
The right tergum is large and placed in the middle of the upper part of the ca- 
