CARPENTER—PYCNOGONIDA. 99 
(fig. 21). Palp 1) as long as proboscis: fifth segment 13 as long as third; sixth and 
seventh equal, together § length of third; eighth and ninth equal, shorter than tenth, 
the three terminal segments together being half as long again as the seventh (fig. 21). 
Oviger 17 total length of body, sixth segment 1} length of fourth (fig. 20). Proportions 
of four terminal segments as 7:6: 6:5 (fig. 22), with five rows of spines very variable 
in form (figs. 22, 23). Leg with thigh equal to first tibial segment, second tibial 
segment 7 shorter, tarsus 14 length of propodus ; terminal claw rather short, only = length 
of propodus (figs. 20, 24). 
Locality. Saya de Malha, Station C 21, 450 fms. One male only. 
The proportionate lengths of body and proboscis and the peculiar upturned form of 
the latter distinguish this species from all described members of the genus. The spines 
on the ovigers are simpler in form than in many species of Colossendeis, those on the 
seventh segment being flattened and somewhat serrate (fig. 23, ), while those on the 
other segments are for the most part sharp-pointed and sickle-shaped (fig. 23, @). 
RHOPALORHYNCHUS, Wood-Mason. 
5. Rhopalorhynchus gracillimus, sp. nov. (Plate 13. figs. 25-32.) 
Length (including proboscis), male 7°5 mm.; female 8°5 mm. 
Body elongate and very slender. Proboscis rather shorter than head and trunk, slenderly 
stalked, with a single prominent dorsal spine (figs. 25, 26). Hye-eminence cylindrical at 
base, subeonical above eyes, with an obtuse rounded apex (fig. 28). Palp nearly half as 
long again as proboscis, with the third segment half as long again as the fourth and 
fifth together, and the fifth 1; as longas the five terminal segments together ; proportions 
of the latter as 5:8:8:8:7 (figs. 25, 29). Oviger very slightly longer than palp, 
with sixth segment slightly longer than fourth; proportions of the four terminal 
segments as 7:6:5:4; claw short, five rows of simple spines (figs. 25, 30, 31). Legs 
with thigh markedly swollen distally in female (fig. 25), slightly in male (fig. 26), as 
long as first tibial segment ; second tibial segment about 75 shorter (fig. 25); propodus 
slightly longer than tarsus; terminal claw only 2 length of propodus (fig. 32). 
Localities. Maldive Islands: Kolumadulu (off a black crinoid), one male and one 
female; 8. Nilandu, one maleand one female ; Haddumati, four females. Saya de Malha, 
Station C12 (47 fms.), one male. 
This curious and delicate species may be distinguished from #. krdyeri, Wood-Mason 
(1873, from the Andamans), the type of the genus, by the single dorsal spine on the 
proboscis (2. kréyert having two) and by the relatively short claw to the foot. . ¢enwis- 
simus (Haswell, 1885, pp. 9-10, pl. 57. figs. 6-9) from Port Denison, Australia, has, like 
R. kréyeri, a very long foot-claw, and a much blunter proboscis than the present species, 
which resembles most closely R. clavipes, Carpenter (1893, pp. 22-5, pl. 2. figs. 1-10), 
from the Torres Straits. The latter has, however, a differently-shaped proboscis with a 
weaker dorsal tooth, while the seventh, eighth, and ninth segments of the oviger are 
equal in length. The great plasticity and range of variation shown by many genera of 
Pycnogonida make it quite likely, however, that intermediate links between these two 
forms, and even between them and R&. tenuissimus, may be discovered later. 
14* 
