42 
well as parastigmatic vessels are present. The distance from the 
endostyle to the first internal longitudinal vessels is considerable; 
in one case 12 stigmata were counted in a row. Between the 
longitudinal bars 6 — 8 stigmata are found in a row. In the lower 
part of the gill-sac the stigmata may be very irregularly arranged, 
forming a network. 
The alimentary canal is very strongly curved, the anus 
cannot be seen from the left side. 
The stomach is short and broad, with 16 —18 longitudinal 
folds and a club-shaped coecum. 
The margin of the anus is two-lipped and a little down-bending. 
The genital organs are developed as polycarps, which is charact- 
eristic of this group. The ? -polycarps are found on the right side of 
the endostyle in the number of about 6. They contain a few ripe 
ova and have a short and broad oviduct. The -polycarps are seen 
on the left side in a number of 4—6; they are pear-shaped, with 
a siender sperm-duet in the narrow end. They are simple and 
undivided. The largest testes are about 1 mm long. A number 
of larvae are often found in the atrium. 
The present species shows in its external features a consider¬ 
able resemblance to A. intermedia Michlsn. and A. bridgesi Michlsn., 
with which species I have been able to compare it direetly, Prof. 
Michaelsen having kindly sent me a pair of cotypes. It has 
also a great likeness to the variety of A. inerustans, which was de- 
scribed as A. emilionis by Michaelsen. Only two of the known 
species have so few internal vessels: A. bridgesi and A. capensis 
Hartm. They have, as the present species, six on each side. A. 
bridgesi has differently shaped J ■ polycarps of complicated structure; 
identity with that species thus is evidently out of question. But 
my species comes very close to A. capensis , and it is not at all 
impossible that they may be identical. The main differences are 
in the external appearance. Hartmeyer writes of the colony. 
„eine basale Masse bildend, aus welcher zwei aufrechte, mehr oder 
weniger keulenformige Kopfe herauswachsen ; . Hartmeyer 
does not mention or figure the dark mantie-vessels, so distinetly 
seen in A. affinis. 
Further the stomach has a somewhat different form, and the 
intestinal loop is not so strongly bent in A. capensis as in A. affinis. 
