ERGASILOIDEA. ^313 



4 



Family MONSTRILLHLE. 



Genus MONSTMLLA, Dana. 



Ceplialoihorax fere cylindricus, k-articidatus. Abdomen h-^-articulatum. 

 Antennce duce. Oculi duo simplices * quoque oculus inferior sicut 

 Pontellis. Truncus buccalis parvulus subconicus, maxitlis pedibusve 

 non munitus. Pedes octo, natatorii. Abdominis segmenta lmum 

 2dumque appendices gerentia ac in Setellis. 



Cephalothorax nearly cylindrical, four-jointed. Abdomen five- to six- 

 jointed. Two simple eyes ; also an inferior eye, as in the Pontellce. 

 Antennae two. Buccal trunk quite small, cylindrical, and not 

 moveable at base. Maxillae and anterior feet obsolete ; four pairs of 

 natatory feet. A pair of abdominal appendages to each first and 

 second segments, besides caudal stylets. 



MONSTEILLA VIRIDIS. 



Gracilis, posticd attenuata. Ocidi superior es remoti. Antennas, b-articu- 

 latce, setis antenna brevioribus. . Abdomen b-articulatum, segmento 

 secundo breviore quam primum vel secundum. Styli caudales oblongi, 

 parvi, divaricati, setis 5 subwquis, diffusis. 



Slender, attenuate posteriorly. Eyes remote. Antennae five-jointed, 

 setae shorter than the antennae. Abdomen five-jointed, the second 

 segment shorter than first or third. Caudal stylets small, oblong, 

 divaricate, setae five, subequal, spreading. 



Plate 94, fig. 1 a, animal, enlarged ; b, profile view ; c, buccal pro- 

 minence, more enlarged ; d, abdomen in profile, with last thoracic 

 segment and natatory feet. 



Sooloo Sea, Harbour of Soung ; taken at 8 P. M., on the 3d of Feb- 

 ruary, 1842. 



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