ON THE OVIPAROUS SPECIES OF ONYCHOPHORA. 383 



were found beneath and in the crevices of bits of rotten 

 wood placed in the vivarium, and a fifteenth, though per- 

 haps laid about the same time, was not found till the 

 vivarium was completely turned out on September 16th. 



The single deposited egg of 0. viridimaculatus was 

 found on April 18th, 1900, amongst rotten wood in which an 

 adult animal had been forwarded to me from Lake Te Anau, 

 New Zealand. The package was unfortunately delayed in 

 transit, and the animal itself was dead when it arrived, so 

 that the deposition of the egg may have been hastened by 

 abnormal conditions. 



Development. — Owing to the great scarcity of material, 

 it is impossible to say much under this head, and the remarks 

 which I have to offer, except as regards the newly laid egg, 

 are based exclusively upon 0. oviparus. Two facts, how- 

 ever, stand out clearly, the first being that the newly 

 deposited egg contains no embryo recognisable by ordinary 

 means, and the second that the development progresses 

 extremely slowly, and may occupy as much as seventeen 

 months from the time of laying to the time of hatching. 



The recently laid egg is filled with a milky fluid containing 

 very many yolk granules, the structure of which has already 

 been described (fig. 17). 



The first embryo, already far advanced in development, 

 was removed on November 30th from the egg found on 

 September 16th, so that it was at least ten weeks old from 

 the time of oviposition, and probably a good deal older. 

 Within the chorion the embryo was surrounded by the thin, 

 transparent, vitelline membrane, which fitted closely on to it 

 and was very difficult to remove. The total length of the 

 embryo, exclusive of the antennae, is about 4 mm. It is 

 spirally coiled, making rather more than one complete turn 

 of the spiral, so that the posterior extremity lies against the 

 side of the neck, pointing in an opposite direction from the 

 head, and the ventral surface occupies the inside of the 

 curve. The form of the body is already very like that 

 of the adult, except that the head is larger in proportion. 



