NARRATIVE OF THE CRUISE. 
861 
“ A very characteristic feature in the life-history of the Pycnogonids is afforded by 
the circumstance that the males fulfil the duty of bearing the eggs on the so-called 
ovigerous legs. However, I have been able to ascertain that this rule, which was 
discovered, by G. Cavanna about 1874, admits of an exception in the case of Nymphon 
brevivav datum, Miers. A specimen with egg-masses on the ovigerous legs had con- 
siderably swollen thighs and large genital pores such as are characteristic of the females. 
On investigating the thighs of this specimen, I found them filled up with well-developed 
ovaries. Moreover, from the great resemblance of the ovigerous legs of the males and 
females, I hazarded the supposition that the Pycnogonids of the genus Colossendeis would 
deal with their eggs in a way differing from that of the species of other genera. 
“ Finally, a few words on the metamorphosis of the Pycnogonids. As a rule the 
larva creeping out of the egg is a little creature with only three pairs of appendages 
(which become later on the cephalic ones) ; still in some cases the degree of develop- 
ment which, the larva has reached, when leaving the egg, is different even for two 
Pycnogonids belonging to the same genus. For example, the larva of Nymphon 
gallicum, Hoek, from the French coast, is a true Protonymphon with three pairs of 
appendages only ; the young Nymphon macrum, Wilson, as well as the young Nymphon 
brevicaudatum, Miers, when hatching, is furnished not only with the three pairs of 
cephalic, but also with one or two pairs of thoracic appendages. The cephalic appendages 
in these latter larvae, moreover, have grown rather weak ; their bodies are much more 
elongate than is the case in the other larvae,” 
