THE ANNALS 



AND 



MAGAZIiNE OF NATURAL HISTORY. 



" perlitora spargite museum, 



Naiades, et circOm vitreos considite fontes : 

 PoUice virgineo teneros hlc carpite flores : 

 Floribus et pictum, divje, replete canistrum. 

 At vos, o Nymphae Craterides, ite sub undas ; 

 Ite, recurvato variata corallia trunco 

 Vellite rauscosis e rupibus, et mihi conchas 

 Ferte, Dese pelagi, et pingui concliylia succo." 



Part hen a F< I. 1. 



No. 88. JULY 1844, 



I. — On the Specific and Generic Characters of the Araneiform 

 Crustacea. By Harry D. S. Goodsir, M.W.S. 



[With a Plate.] 



After a careful examination, the parts of the Ptjcnognnid/B 

 which are found to afford the most decisive characters for the 

 proper classification of the species are — the ocular tubercle, the 

 palpi, oviferous legs, and tarsi. The first of these organs affords 

 very valuable and sure characters, especially in the determination 

 of the genera, but unfortunately has never been properly studied. 

 It is therefore the object of the present communication to illus- 

 trate the characters of this organ. These animals, when examined 

 by the naturalist, are generally lying in such a way as to hide this 

 organ altogether. To see it properly the animal must be viewed 

 in profile. 



In Pycnogonum and all the other nonpalpate genera, we find 

 the ocular tubercle standing at right angles with the segment of 

 the thorax from which it arises, and ^-ith one exception {Phoxi- 

 chilidium), in a line between the first pair of legs. In Phoxichilus 

 the tubercle is pointed, but in all the others it is truncated. 



Pycnogonum Bala^narum. 

 This Pycnogonum when viewed in profile presents the appear- 

 ance showTii in PI. I. fig. 1. The rostrum is flask-shaped, and 

 the anterior extremity slightly bulging and rounded. The ocular 

 /Ir- Ann. 6: Mag. N. Hist. Vol. xiv. B 



