188 NATURAL HISTORY. 



fifth joint of the legs, so that there are eight of them. In the females, however, the eggs are extruded 

 from an aperture in the second joint, and passed from this to a pair of accessory limbs springing from 

 the first segment beneath the first pair of true legs, and to these they remain adherent until the young 

 are hatched. 



The larvae when just hatched possess an unsegmented body and only two pairs of jointed legs ; 

 their chelicerse, which form nippers, often bear long lateral filaments, presenting a remarkable 

 resemblance to the flagella of the antennae in Crustacea, in fact, the little creatures may be well 

 compared to the Nauplius form, as it is called, of many Crustaceans. 



These very singular creatures are found in all seas, chiefly near the coasts, where they conceal 

 themselves under stones, or cling to seaweed, and even to other animals. Occasionally they are 

 met with adhering to fishes. In their movements they are slow and clumsy. A moderate 

 number of species are known, generally of fair size, but in some deep sea dredgings large forms 

 have been met with. They constitute two families, the Pyciiogonidse and Nymphonidae. 



The former (Pycnogonidae) are generally of a more Crustacean aspect, and present a considerable 

 external resemblance to certain Isopod Crustacea. They possess no chelicerse or palpi Pycnogonum 

 littorale is a common species upon all European coasts, where it crawls about under stones and among 

 seaweed, with masses of which it is not unfrequently found floating upon the surface of the sea, 

 This species is nearly half an inch long. 



The Nymphonidse have pincer-like chelicerae and palpi, and much longer legs than usually 

 occur in the preceding family. The egg-bearing false-legs ako are usually much longer than in the 

 Pycnogonida?, with which these animals agree generally in habits. The commonest European species 

 (Nymphon gracilis) is about a quarter of an inch long. AmmotJwa pycnogonoides, the species figured 

 (p. 187), belongs to this family. 



W. S. DALLAS. 



