362 APPENDIX. 



we find this form accompanied by members of a curious 

 genus characteristic of the Australian province, — 

 Ampullacera, the Ampullacera Quoyana being the Bris- 

 bane Water species, and A. avellana, that of New Zealand. 

 In the latter case an Assiminea is its companion. A very 

 curious fact noted during the expedition was the presence 

 of a Unio living within the iufluence of salt water, in the 

 River Brisbane. 



Shells inhabiting mud, S/'c. among mangroves. 

 These belong to the Indo-Pacific province. Some are 

 found on the mangroves themselves. Such are the 

 Littorina scabra, on the trunks and branches of mangroves 

 among islets in Trinity Bay ; a Phasianella inhabiting the 

 trunks and branches of Rhizophora at the Percy Isles ; 

 a Littorina on the leaves of Aigceceras fragrans at Port 

 Curtis, Auricula angulata, and rugulata on the trunks of 

 mangroves at PortEssington, aniMonodoyitaviridis on their 

 roots at Night Island ; a new and very beautiful Ostrea was 

 found on the roots of mangroves among Low Islets in 

 Trinity Bay . In the last named locality a Cytherea inhabited 

 the mud around their roots. At the Three Islets several new 

 species of Melampus, a Nerita and a Cyrena lived in a 

 like habitat, and at Port Essington Cerithium Kieneri, 

 was found in the same situation. The fine Cyrena 

 cyrenoides lives among the roots of mangroves in the 

 Louisiade Archipelago. 



Littoral Zone. — Of the many living Gasteropoda taken 

 in this region, very few are new species. Of Patelloid 

 forms we have a new Fissurella and Parmophorus convexus 

 at Port Dalrymple, accompanied by Haliotis ncevosa, and 

 species of Patella and Siphonaria. In the more tropical 

 regions, Haliotis asinina and varia, another and distinct 

 Patella, two FissurellcB and a Scutella were collected. Of 

 convolute shells the littoral species gathered were all Indo- 



