Gatty Marine Laboratory, St. Andrews. 135 
Malaquin * gives also an account of the sexual and asexual 
phases of Salmacina dysteri :— 
I. Phase of a young protandrous form. The male genital 
segments are incorporated with the thorax, and are sterile. 
II. Phase is that of asexual reproduction, or schizogenesis. 
In this the animals present incomplete male sexuality, mani- 
fested by the production of a few spermatozoa which attain 
maturity. 
Ill. Phase—hermaphroditism. Gonads (male and female) 
are situated in distinct segments—the male in the three (two 
to four) anterior abdominal segments, the female in the eight 
to ten segments which follow. The circulation in Salmacina 
and Filograna resembles that of the Serpulids in the particular 
reticulation of vessels distinct from the celom. There are 
branchial and ventral vessels. Around the intestine is a 
vascular sinus, as in Serpulids and Sabellarians. In Salma- 
cina and Filograna this sinus lies between the endothelium 
splanchnoplanique of the ccelom and the intestinal epi- 
thelium. This part of the hemocele represents exactly the 
primitive blastoceele. 
The same author f (1911) gives an elaborate disquisition 
on the phases of Salmacina, grouping them as follows :— 
I. The sexual forms, including the young protandrous forms, 
with three to five segments in the thorax, two intermediate, 
and six abdominal segments. IL. The unisexual, rarely 
female, less rarely male. The female is 24 mm. long, with 
three thoracic segments, an intermediate asetigerous segment, 
and six to eighteen abdominal distended with ovocytes. 
Probably this becomes hermaphrodite. The male is 1?- 
24 mm., with seven thoracic segments, sixteen ripe abdo- 
minal segments, and three or four terminal. 
The hermaphrodites have eight branchiz, eight thoracic 
segments, then two or three achetous segments ; immediately 
behind are two or three with male gonads, and the succeeding 
ten have female gonads with red ova. They reach 6-7 mm., 
and may have fifty abdominal segments. In some herma- 
phrodites male elements predominate, the female segments 
being reduced. In others a hermaphrodite segment occurs at 
the limit of the male region, the male elements being on one 
side, the female on the other. He has also seen a herma- 
phrodite gonad. 
The metamere, as a rule, is unisexual, but, as mentioned, 
between the male and female regions a hermaphrodite one 
* Assoc. Francaise Adv. Se. Lille, 1909, p. 139. 
+ Zool. Anzeiger, Bd. xxxvii. p. 201. 
