CYMOTHOIDEA. 759 



rounded behind, emarginate (?) at middle. Caudal stylets long, 

 branches unequal, outer branch styliform. 



Plate 50, fig. 7 a, body, enlarged one and a half diameters ; b, side 

 view, showing epimerals, enlarged two diameters. 



Rio Janeiro. 



Length, one inch ; breadth, six to six and a half lines. Like the 

 maculata and affinis, the five anterior thoracic segments are obtuse 

 either side ; but the epimerals are not all acute, those of the second 

 and third thoracic segments being rounded, and as long as the tergal 

 part of the segment, and those of the third segment are hardly acute. 

 In the right caudal stylet, the outer branch is obtuse, and the inner 

 branch is the longer and substyliform ; while in the left, the inner is 

 the shorter and is obtuse, and the right is long and slender styliform. 

 The posterior legs are smaller than the penult. 



Nerocila brasiliensis. 



Corpus duplo longius quam latum, oblongo-ellipticum vdlde convexum. 

 Thorax oblongus, segmentis 3 posticis lateraliter acutis sed non valde 

 divaricatis. Epimerce acuminata?, lateris utriusque 3 4:vepostica3 acutos. 

 Abdomen vix oblongum, segmentis quinque lateraliter productis, prce- 

 cipue duobus anticis, ultimo scutiformi ad basin latiore, paululo trans- 

 verso, postice semicirculari sed medio paulo angulato, obtuso. Styli 

 caudales abdomine multo longiores, ramis incequis, externo fere cylin- 

 drico, acuminato, interno compresso. 



Body long-elliptical (twice as long as broad), very convex. Thorax 

 much longer than broad ; three posterior segments laterally acute, 

 points prominent, but not much divaricated. Epimerals acuminate, 

 those of fifth, sixth, and seventh segments acute. Abdomen hardly 

 oblong ; first five segments laterally produced, especially the two ante- 

 rior, the fifth but little wider than following segment ; last segment 

 scutiform, broader at base, distinctly shorter than broad, posteriorly 

 semicircular, with the middle angulate, obtuse. Caudal appendages 

 straight, acute ; outer branch nearly cylindrical, acuminate ; inner 

 compressed. 



