South American Rotifero.. By J. Murray. 245 



In my collections also the Loricata constitute far the most 

 important part. The 13delloida may be as numerous in species, 

 but they are only of interest from the distributional point of 

 view, as the South American Bdelloid fauna shows very little 

 peculiarity. Among the Loricata, on the other hand, many curious 

 new forms were found. These were most numerous among tlie 

 Cathy pnidae, which are dealt wath in a succeeding paper of this 

 series. In the four families treated of here, thirteen species were 

 identified, excluding those noted in the paper on Bolivia and Peru, 

 already published. Nine of them are new for South America. 



LIST OF SPECIES COLLECTED. 



In Brazil. 



DiascMza gihha Ehr. *Rattulus pusillus Laut. 



*D. exigua Gosse. * Polychsetus collinsi Gosse, and 



D. cseca Gosse. variety. 



*Diurella loorcellus Gosse. * Stephanops tenellus Bryce. 

 *D. voluta sp. n. Salpina mucronata Miiller. 



*Battulus hraziliensis sp. n. *Diplax trigona Gosse. 

 *R. stylatus Gosse. 



In Chile. 

 Rattulus pusillus Laut. R. longiseta Schrank. 



Notes on the Species. 



Diurella voluta sp. n. Plate X, figs. 17a-17d. 



Specific Characters. — Of medium size, very hyaline; toes nearly 

 equal, with several sub-styles. Keel of immense size, enveloping 

 great part of the body as in the muUusc Voluta ; springing from 

 the back it curves strongly to the right till it reaches below the 

 ventral surface. Large red eye. 



General Description. — Exact measurements were not obtained, 

 as I spent all my time over the two specimens I had in trying to 

 make out the nature of the extraordinary hyaline envelope. I 

 believe the lateral view is drawn to about the same scale as the 

 other figures on the same plate, i.e., the envelope about 140 fx in 

 length, the toes 40-50 yit. Apart from the keel, the body is of 

 the common shape of the smaller species of the genus, such as 

 D. tigris. The keel is unlike any other, in that it extends beyond 

 the trunk to the very end of the extended head-sheath, and 

 posteriorly far beyond the end of the foot. The head -sheath is 

 evidently not retractile, as shown in figs. Via and 17c, where the 



