1912.) R.B.SryMOUR-SEWELL: Surface-Living Copepoda. 37 
Wie 
Genus Pontellopsis, G. Brady. 
Pit seminvee fig, 5. 
Pontellopsis herdmani, Thompson and Scott, 
Oyster Fisheries (Suppl. Report vii), vol. i, p. 253, pl. it, 
figs. I5—-17 (1903). 
Pontellopsis macronyx, A. Scott, The Copepoda of the Si- 
boga Expedition, pt. i, p. 137, pl. liv, figs. I—10 (1909). 
On 
Pontellopsis herdmani, ‘Thompson and Scott. 
Ceylon Pearl 
Occurrence: ecalities AB; Cel bat. ©) be 
A large number of specimens, both males and females, were 
obtained. The males correspond exactly with the description of 
Pontellopsis macronyx, A. Scott, from the ‘‘ Siboga’’ collection. 
The females however present certain differences and are exactly 
intermediate between Pontellopsis macronyx and _ Pontellopsis 
herdmant, which was described by Thompson and Scott from 
Ceylon and to which no corresponding male was obtained. 
Considering the differences between the two forms obtained 
from Ceylon and the waters to the east of Borneo, Scott was quite 
justified in making them different species, but the discovery of a 
third and intermediate form from the Burma coast indicates that 
in reality we are dealing with a single very variable species, and 
I propose to combine the three under the name of P. herdmanz. 
In the following table I have given the main characters of the 
three forms :— 
P, herdmanti. 
Total length 
Length of abdo- 
men and fur- 
ca. 
Abdomen 
Furcea .. 
Rostrum 
Antenna 
| 
| 
P. macronyx. 
I‘O mm. 
1°97 mm. 
Intermediate 
form. 
1°64 mm, 
Contained twice in cephalo- Contained 2} | As P. macronyx. 
thorax. 
times. 
Composed of 2 joints, Ist 2 joints. Genital) 2 joints. Genital 
segment twice as large as 
2nd, two thorn-like pro- | 
jections on right side 
Rami twice as long as broad, 
fine hairs on inner surface, | 
5 short non-plumose setae. | 
Long, narrow and bifid. 
16 jointed (judging from the 
fig segments 3 and 4 are 
each composed of 3 seg- 
ments fused together), ex- 
tend toend of thorax. Re- 
lative lengths as follows : 
ee25, Bia vile Ia (6). 
Oy Fs Gees Ge 
segment long, 
two spines on 
each side. 
| Furcal 
short, 
setae. 
Rami long and 
slender. 
20 jointed, ex- 
tend to end of 
thorax. 
joints 
5 short 
segment long. 
Spines variable 
from 2 to 4. 
| As P. herdmant. 
Ditto ditto. 
As P. herdmani. 
Segments 3 and 
4 each compos- 
ed of 3 partially 
fused segments. 
Relative lengths 
as in P. herd- 
mant. 
