524 PYCNOGONIDA ’ CHAP. 
doubt that they contained the remains of larvae of a Pyenogonid, 
so that the deep-sea Pycnogonids, which are so abundant, very 
possibly pass through their early stages in deep-sea Stylasteridae. 
.. . The gastrozoids containing the larvae were partly aborted.” 
A Pyenogon larva, doubtfully ascribed to Nymphon, has been 
found living in abundance ectoparasitically on Zethys in the Bay 
of Naples.’ 
Habits.—Of the intimate habits of the Pycnogons we can 
say little. Pycnogonum we often find clinging, as has been said, 
close appressed to some large Anemone (7'ealia, Bolocera, etc.), 
whose living juices it very probably imbibes. The more slender 
species we find climbing over sea-weeds and Zoophytes, where 
sometimes similarity of colour as well as delicacy of form helps 
to conceal them; thus Phowichilidiwm femoratum (Orithyia 
coccinea, Johnston) is red like the Corallines among which we 
often find it, P. virescens green like the filamentous Ulvae, the 
Nymphons yellowish like the Hydrallmania and other Zoophytes 
which they affect. On the New England coast, according to Cole, 
the dark purple Anoplodactylus lentus, Wilson (Phoaichilidium 
maaxillare, Stimpson), is especially abundant on colonies of 
EHudendrium, whose colour matches its own, the yellowish Tany- 
stylum orbiculare frequents a certain yellowish Hydroid, and of 
these two species neither is ever found on the Hydroid affected 
by the other; while, on the other hand, Pallene brevirostris, whose 
whitish, almost transparent body is difficult to see, is more 
generally distributed.” The deep-sea Pyenogons (Colossendeis, 
Nymphon) are generally (if not universally) of a deep orange- 
scarlet colour, a common dress of many deep-sea Crustacea. 
The movements of the Pycnogons are singularly slow and 
deliberate ; they are manifestly not adapted to capture or to kill 
a living prey. Linnaeus accepted from J. C. Konig the singular 
statement that they enter and feed upon bivalve shells, “ Myti- 
lorum testes penetrat et exhaurit”’; but the statement has never 
been reaffirmed. 
1 Hugo Mertens, Afitth. Zool. Stat. Neapel, xviii., 1906, pp. 136-141. 
* One is tempted to explain such cases as the above of harmonious or identical 
coloration by the simple passage of pigments unchanged from the food. 
° Fabricius says of his Pycnogonum (Nymphon) grossipes, ‘‘ Vescitur insectis et 
vermibus marinis minutis ; quod autem testas inytilorum exhauriat mihi ignotum 
est, dum nunquam intra testam mytili illud inveni, licet sit verisimile satis,” 
Fauna Groenlandica, yp. 231. 
