THE ANNALS 



MAGAZINE OF NATURAL HISTORY. 



" per litora spargite museum, 



Naiades, et circum vitreos considite foutes : 

 Pollice virgineo teneros hlc carpite flores : 

 Floribus et pictum, divas, replete canistrum. 

 At vos, o Nymphae Craterides, ite sub undas ; 

 Ite, recurvato variata corallia trunco 

 Vellite muscosis e rupibus, et mihi conchas 

 Ferte, Deae pelagi, et pingui conchylia succo." 



Parthenii EcU \. 



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 Pycnogonida 

 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 with one exception (Phocci- 

 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 Balamarum. 



This Pycnogonum when viewed in profile presents the appear- 

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

 the anterior extremity slightly bulging and rounded. The ocular 



Ann. §■ Mag. N. Hist. Vol. xiv. B 



