Echiuroid Worm— FISHER 
275 
brown spots, perhaps the nephric elements, 
although ciliated funnels cannot be recognized. 
Alimentary canal very long and filled with 
coarse "sand.” No caecum present. Foregut 
without obviously differentiated subdivisions 
recognizable from outward appearance. Seg¬ 
ment adjacent to ring blood-vessel (B 2 ) some¬ 
times set off by a slight constriction. Very long 
segment of the intestine, between B 2 and be¬ 
ginning of siphon, apparently without ciliated 
groove. (This presiphonal segment is generally 
short.) In one specimen 50 mm. long, with 
empty and relaxed intestine, presiphonal seg¬ 
ment can be traced for 40 mm. before a break 
occurs. It is almost certainly longer. Foregut 
25 mm. in length. In another specimen a seg¬ 
ment about twice as long as foregut is without 
siphon, although siphon is recognizable over 
an extensive portion of the midgut. Entire 
intestine about ten times contracted body length; 
in specimens examined in a most wonderful 
snarl, complicated in all but one by sausage-like 
swellings filled with sand and shell fragments. 
Vascular system (Fig. 1 , a) of usual Thalas¬ 
sema type, with well-developed ring vessel and 
some slight variations in the details of the con¬ 
nection with the neurointestinal vessel (B 3 ). 
(It may be remarked that the length of the 
neurointestinal varies from half the length 
shown in Figure 1, a to five times that length, 
depending entirely upon position of the end of 
the forgut, which has great freedom of move¬ 
ment.) 'In one specimen, killed while passage 
from stomach to intestine was distended by 
sand, ring vessel (B 2 ) three times usual diameter 
in preserved specimens. 
Type: In the collection of the United States 
National Museum. 
Type locality: Honolulu; reef south of harbor, 
in tide pools, June 6, 1902. Collected by W. K. 
Fisher. 
Specimens examined: Honolulu reef, 15; 
Puako Bay, Hawaii, 2. I have also examined 
several collected by R. W. Hiatt at Halape, 
Hawaii, where they were found in sand under 
rocks. 
Discussion: This species is probably rather 
closely related to Thalassema semoni Fischer 
(1896: 338, Fig. 4; Amboina) but the descrip¬ 
tion lacks all details of the alimentary canal 
and figures of importance: Proboscis lost; larger 
of the two specimens 55 mm.; skin bluish-gray, 
rather thin and translucent; musculature not 
split into bundles; papillae cover skin almost 
without intervals, though more concentrated 
at posterior end; setae small; nephridia four, 
with spiral tubes; anal vesicles thin, brown, 
longer than half the body; they are attached 
to body wall by muscles; caecum not observed. 
Fischer states (1914: 19) that Thalassema 
sabinmn Lanchester (1905: 40, Tale Sab, Sin- 
gora) is a synonym of semoni. However, Pra- 
shad (1919: PI. 11, Fig. 10) figures a dissec¬ 
tion of sabinum, which shows a well-developed 
caecum and short anal vesicles. The proboscis 
is adherent, being an important respiratory or¬ 
gan owing to the ecology of the species. This 
figure also indicates that the presiphonal seg¬ 
ment of intestine is short. A. sabinus is ob¬ 
viously not close to porcellus and is probably 
not the same as semoni. 
No true Thalassema has been recorded from 
the Hawaiian Islands. Other echiuroids which 
I have examined from the islands are: Oche- 
tostoma erythrogrammon Leuckart and Riippell, 
Nawiliwili, Kauai (A. E. Verrill), and Halape, 
Hawaii (R. W. Hiatt); Ochetostoma manjuo- 
dense Ikeda, Halape, Hawaii (R. W. Hiatt); 
Anelassorhynchus inanensis (Ikeda), Halape, 
Hawaii (R. W. Hiatt). There are undoubtedly 
other species present in these waters. 
As the genera allied to Thalassema are rather 
difficult to distinguish, the following synopsis 
may prove useful. 
Keys to other genera of Echiuroidea, prin¬ 
cipally Bonelliidae, and figures of anatomy will 
be found in Fisher, 1946. 
