1888.] 



Explanation of the Plates. 



Plate 1. 

 Latonopsis australis, n. gen. & sp. 

 Fig. 1. Adult ovigerous female, viewed from left side; magni- 

 fied 74 diameters. — The right antenna is extended, 

 the left reflexed and closely appressed along the shell, 

 an attitude often assumed by the animal, when exa- 

 mined under the microscope in a small quantity of 



- 2. Another female specimen, from below, with both an- 



tennae extended and the setae of the infero-posteal cor- 

 ners of the valves exposed; magnified 56 diameters. 



- 3. One of the antennulae, magnified 89 diameters. 



- 4. One of the antennae ; same enlargement. 



- 5. A leg of 2nd pair, expanded and viewed from the an- 



terior side. 



- G. Tail with adjoining part of body, viewed from left side. 



Plate 2. 



Figs. 1—5. Simocephalus australiensis, (Dana). 

 Fig. 1. Adult ovigerous female, viewed from left side; magni- 

 fied 46 diameters. 



- 2. Anterior part of body of another specimen, from below; 



same enlargement. 



