200 L. A. BORRADAILE. 
2. Systematic List. 
Subfamily Carupinae. 
Genus Lupocyclus Ad. and Wh., 1848. 
1. Lupocyclus strigosus Ale. 1900. Alcock, Iv. p. 24. 
Dredged in Kolumadulu on a bottom of dead and broken shells in 35 fathoms of water, 
All previous specimens have been dredged in the neighbourhood of India in 15—58 fathoms. 
Subfamily Thalamitinae. 
Genus Lissocarcinus Ad. and Wh., 1848. 
2. Lissocarcinus laevis Miers, 1886. Alcock, Iv. p. 21. 
Dredged in South Nilandu on a bottom of hard sand in 36 fathoms of water. 
3. Lissocarcinus polybioides Ad. and Wh., 1848. Alcock, rv. p. 19. 
Dredged in Mulaku on a bottom of mud with weed, in 28 fathoms of water. 
4. ILnssocarcinus orbicularis Dana, 1852. Alcock, rv. p. 20. 
This crab lives symbiotically’ with the teat-fish (Holothuria nigra). It hides under or 
among the tentacles, coming out from shelter at times, perhaps to feed, and crawling all 
over the body of its host on which it crouches if disturbed. Its dark purple colouring 
with white spots is protective, resembling the sticky black skin of the teat-fish with 
grains of coral sand adherent. Paler brown forms live on other Holothurians to whose colour 
their own is adapted. The other two species taken by the Expedition are roughly speaking 
sand-coloured, and there is no record of their living symbiotically with other organisms. 
The females of LZ. orbicularis show a very perfect condition of an arrangement found in 
various other swimming crabs. That is to say, there is a well-developed brood-pouch formed 
by a deep sternal hollow surrounded with a fringe of hair and floored by the abdomen, 
whose sides are also edged with hair. One specimen had many fully hatched zoaeas in this 
pouch, and it would be interesting to know how long these young remain there, and how 
much of their development is passed there. 
The species was taken on the shore and also dredged. It was found in Minikoi, Hulule, 
Male Atoll, Furnardu velu?, Miladumadulu, South Nilandu, and Mulaku. 
Genus Charybdis de Haan, 1835. 
5. Charybdis (Gonioneptunus) truncata (Fabr.). Alcock, Iv. p. 67. 
The size and shape of the teeth on the antero-lateral edge are not constant. This is 
probably the reason why the descriptions of different writers do not quite agree. Alcock 
1 The words “ symbiosis” and ‘‘commensalism” appear associated organisms is of the same nature. 
to be often used as synonymous, but the latter should 2 [For definition of this term see p, 155. Ep.) 
obviously be restricted to cases where the food of two 
