200 



TURNER. 



[Vol. II. 



high, while the female is 4.00 mm. long and 2.00 mm. high. 

 But there are two respects in which the shell of the male differs 



from that of the female : first, 

 the shell of the female is 

 opaque, or nearly so, but that 

 of the male is so transparent 

 that the testes and append- 

 ages may be seen through 

 it ; second, there are a few 

 blotches on the outside of 

 the female shell, but on the 

 outer side of the large valves 

 of the male shell, and attached 

 to the dorsal margin of the 

 same, there is a pair of smaller 

 valves. It looks as though 

 the creature had partially sloughed one pair of valves, and then 

 grown a larger pair beneath them. It is well known that cer- 

 tain Cladocera l^Ilyocryptns sordidiis 

 Lievin) have this habit of partially 

 sloughing the lorica and then grow- 

 ing a new one attached to the old ; 

 but, so far as I know, this is the 

 first time that an Ostracod has been 

 known to do so. 



The first antennae of both male 

 and female are alike ; but the 

 second antenna of the male, unlike 

 that of the female, has a slender 

 ultirnate joint, and the three term- 

 inal claws arise from the penultimate 

 segment (Fig. i). 



The first maxilla of the male is 

 similar to that of the female, the 

 two large claws being smooth ; but, 

 as usual among male Ostracods, the second maxillae of the male 

 are modified for clasping. The structure of the male maxillae 

 is illustrated in Fis;. 2. Fig:. 2 also shows the difference in size- 



