BV riiOFESSOK T. THOMSON Fl-YNX, B SC. 71 



Rhopalorhynchus tenuissimus, Haswell. 



(PI. XVIII., figs. 1-3.) 



1884, Colo^xendei-i touiis.sima, Haswell, 1884, p. 1029, pi. 



56, figs. 5-8. 

 1893, Rhopalorhynchus: rfarip/r^, Carpenter, 1893, p. 24, 

 pi. II., figs. 1-10. 



1908, JiliopcHorliynchus tenuissimus, Lonian, 1908, p. 24. 



1909, Rhopalorhynchus tenuissimus, Thompson, 1909, p. 

 533. 



Specimen. — Australian Museum Collection, G519o, 

 holotype, male. Port Denison, Queensland. 



Description. — It is only necessary to supplement 

 in a small degree Prof. Haswell's account of this species. 



Vepha/on is short and narrow, not expanded in front. 

 Segmentation is distinct. 



Ocular tubercle is situatevl on the posterior portion of 

 the cephalon. It is cylindrical with a small rounded cone 

 at tlie apex. 



Abdomen is present, but as usual in this genus is cjuite 

 minute. 



Palps are ten jointed. The first joint is short and 

 thick and expanded at the extremity; the second is very 

 small ; the third joint is very long and slender ; the re- 

 maining joints are as described bv Haswell. 



Ovif/ers. — Tlie character of the q)ines of vhe last 

 few joints cannot be determined with accuracv as the 

 joints had not been cleaned before the specimen had been 

 mounted originally. The spines, however, seem to be long 

 and sharp and arranged in several rows. 

 Mea-^uriDiiiifs : — 



mm. 



Proboscis, length 4.41 



maximum diameter 1.05 



Trunk, length 5.28 



width behind first crui'igers 29 



,, ,, second ,, 32 



width across ,, ,, 1.58 



Palj), first joint 12 



second 07 



third 2.92 



fourth 19 



fifth .-.. 1.53 



sixth 31 



seventh,, ... 38 



eighth 42 



ninth 40 



tenth 38 



