44 ON THE STRUCTURE AND SYSTEMATIC POSITION OF CYSTOPELTA, 



ON THE STRUCTURE AND SYSTEMATIC POSITION 



OF CYSTOPELTA. 



By C. Hedley, F.L.S. 



Assistant in Zoology, Queensland Museum. 



(Communicated by John Brazier, F.L.S.) 



(Plate I.) ' 



The privilege of investigating this interesting animal, I owe to 

 the courtesy of Mr. Brazier, who allowed me to examine a couple 

 of specimens collected by Mr. R. Helms in Wilson's Valley, on 

 the flanks of Mt. Kosciusko, at an elevation of 5000 ft. 



Nothing resembling it has, so far as I am aware, been recorded 

 from Australia, but the mollusk at once recalled the description of 

 Cysto-pelta petterdi, Tate, (Trans. Roy. Soc. Tas. 1880, p. 17) to 

 which externally it closely corresponds. Never having had an 

 opportunity of examining the Tasmanian species, I shall assume 

 that the N.S.W. animal is conspecific with G. fetterdi, though the 

 difference in colour, habitat, &c,, would lead one to suppose that 

 were a comparison instituted specific differences would be dis- 

 tinguished. To any Tasmanian naturalist who would assist me 

 with specimens of C. 'petterdi for examination I should be most 

 grateful. 



The spirit specimen I have befoi'e me measures along the sole of 

 the foot 15 mm., from the sole of the foot to the top of the visceral 

 hump 7 mm., from the anterior to the posterior end of the mantle 

 12 mm., from the mouth to the pulmonary orifice 5 mm. The 

 caudal mucous pore is small, not cleft to the sole, and from it a well- 

 marked pedal line extends to the lips. The posterior half of the 

 foot is free ; of this the anterior portion is broadened into a saddle- 

 like space upon which rests the visceral mass as in Helicarion. 



