2184 CRUSTACEA. 



at the posterior angles. Anterior antennae of female half as long as 

 cephalothorax, eight- or nine-jointed, setae all short; of male shorter 

 three basal joints very short, fourth very stout, subovate, half as 

 long as the antenna, last joint (perhaps a double one) a slender 

 finger, half as long as the fourth. Caudal stylets scarcely a fourth 

 the length of the abdomen, second seta longer than the abdomen, 

 the first a short spine. 



Plate 83, fig. 3 a, male, enlarged; b, female antenna; c, caudal 

 setae, magnified ; d, bag of eggs, enlarged. 



Fresh-water pools, Valparaiso, May, 1839. 



Length, one-twenty-fourth of an inch. Colourless and nearly trans- 

 parent. Caudal stylets scarcely three times their breadth in length. 

 Third seta of the stylets about half the length of the second. In 

 anterior antennae of female the two terminal joints are longer than 

 the two preceding, and the fifth from the apex is the longest. Ex- 

 ternal ovarian sacs, dark purple, and each containing five or six large 

 eggs ; they extend as far back as base of stylets. 



Cyclops Mac Leayi. 



Feminae : — CepJialotJiorax dbdomine valde longior. Antennae anticce 

 Imigce (cephalotlwracem cequantes), ad basin paulo crasswres; artir 

 culo secundo oblongo, 5—6 sequentes brevissimos simid sumtos longv- 

 tudine fere cequante, 10 reliquis paulum oblongis, septimo hngwre; 

 setis articuli secundi et septimi parum elongatis, duorum subultimorum 

 totis brevibus, ultimi articulum longitudine vix super antibus. Styli 

 caudales tenues, duos articulos abdominis longitudine cequantes, seta 

 secundd dbdomine breviore, primd fere styli longitudine. 



Cephalothorax much longer than the abdomen. Anterior antennas 

 as long as cephalothorax, rather stout at base, many-jointed, second 

 joint oblong, nearly as long as the five or six following together, 

 which are each very short, remaining ten a little oblong, the 

 seventh longest, setae of second and seventh joints somewhat elon- 

 gate, on the two subultimate joints all shorter than the joints, on 



