CHAPTER XXI 



PYCNOGONIDA 



Eemote, so far as we at present see, from all other Arthropods, 

 while yet manifesting the most patent features of the Arthropod 

 type, the Pycnogons constitute a little group, easily recognised 

 and characterised, abundant and omnipresent in the sea. The 

 stvident of the foreshore finds few species and seldom many 

 individuals, but the dredger in deep waters meets at times 

 with prodigious numbers, 

 lending a character to 

 the fauna over great 

 areas. 



The commonest of our 

 native species, or that at 

 least which we find the 

 oftenest, is Pycnogonum 

 littorale {Phalangium lit- 

 torale, Strom, 1762). 

 We find it under stones 

 near low-water, or often 

 clinging louse-like to a 

 large Anemone. The 

 squat segmented trunk 

 carries, on four pairs of 

 strong lateral processes, 

 as many legs, long, robust, eight -jointed, furnished each with 

 a sharp terminal claw. In front the trunk bears a long, stout, 



^ Pycnogonides, Latreille, 1804 ; Podosomata, Leach, 1815 ; Pychnogonidcs ou 

 Crustac6s aranMfornies, Milne- Edwards, 1834 ; Crustacea Haustellata, Johnston, 

 1837 ; Pantopoda, Gerstaecker, 1863. 



501 



Fig. 262. — Pycnogonum littorcde, Strciin, x 2. 



