210 
festly convex behind the middle. But specimens intermediate between 
those mentioned are very common; fig. 6 exhibits an ovigerous 
female with the head and the abdomen somewhat less expanded 
than in the typical "forma WNordmanni', while fig. 2 shows an- 
other adult female with the lateral and latero-anterior parts of the 
head a little more expanded than in the typical J. marina and 
with the abdomen proportionately a little broader. And specimens 
intermediate between the two last-named specimens are also found. 
— Furthermore I have examined the male copulatory organs which 
in the Asellota show excellent characters, but the differences found 
between these organs of a very expanded and a not expanded 
male are extremely small and scarcely of any importance at all: 
in the true I. marina the copulatory appendix had its distal thread- 
shaped part proportiona- 
tely a little longer (fig. 8) 
than in the expanded spe- 
cimen (fig. 7), while the 
membrane along the di- 
stal part of the outer 
margin of the large plå- 
Figs 7—8. Iæra marina Fabr. te terminates proximally 
Second male pleopod. suddenly mn ag 
way, but in the broad specimen it tapers gradually until it disappears. 
Most of my nearly innumerable Danish specimens are without 
special locality, but animals taken during later years have the 
statements on the localities preserved.  Judging from these the 
specimens taken at the shore itself belong to 7. marina sens. Sars, 
while sometimes this form, sometimes the form J. Nordmanni, and 
sometimes both forms together have been taken in depths from 10 
to 12 feet or more. 
Ifølge Meinert er 1. marina meget hyppig "i. vore sydlige 
Farvande og langt op i Østersøen”, saaledes ogsaa taget ved Born- 
holm; den er særdeles udbredt i Storebelt, Lillebelt, Samsøbelt og 
Aarhusbugten, er taget i Mariagerfjord, ved Indløbet til Limfjorden, 
