352 Transactions of the Society., 



Cathijiona Indivigii Eck. {So). Plate XIY, figs. 23a-235. 



Syn. Distyla ludioigii Eck. 1884. 

 D. oxijcauda Sten. 1898 (52). 



Description. — Of moderate size, sub-rhomboid ; dorsal plate 

 larger, truncate at both ends ; anterior margins — dorsal nearly 

 straight, crenulate, ventral incised in rounded curve — bounded by 

 sharp spines ; posterior segment produced in large median cuspidate 

 process. Dorsal surface faceted with nearly regular haxagons. 

 Toes short, incurved, tapering to acute point. 



Length of contracted lorica 150 fx, of dorsal plate 110 /x, width 

 of dorsal plate 75 /it, of anterior margin 40 /x. The lateral and 

 posterior sulci are of moderate depth. The faceting of the dorsal 

 plate appears to be of a pattern found uniformly in a whole series 

 of species — C. ploenenisis, C. stokesii, 0. signijera, C. ohioensis. In 

 all of these there may be reckoned five transverse rows of mark- 

 infjs, of which those near the middle line are distinct hexagons. 

 Next the posterior border there are two rounded marks, in front of 

 those three distinct hexagons, with one exactly median ; in the next 

 row four hexagons, alternating with the three ; again a row of three 

 in front of these, with one median ; in row next anterior margin 

 more irregular marks. The transverse rows are continued by more 

 obscure hexagons on each side of those indicated above. 



Habitat. — Pond in Botanic Gardens, Eio. 



Cathypna sp., undescribed. Plate XIV, tigs. 30a-30c. 



Found previously by Mr. Harring, of Washington, and to be 

 described by him in a paper, which will be published about the 

 same time as this. 



Description of Brazilian example. — Of moderate size, oval, 

 dorsal plate wider than ventral. 



Length of contracted lorica 95 fx, of dorsal plate 80 /t, of toe 

 25 /x; breadth of dorsal plate 65 /x, of ventral plates 60 /x, of 

 anterior margin 45 /x. 



The dorsal anterior margin is convex, and is bounded by small 

 spines. The surface is faceted, the pattern being that commonest 

 in the genus, and seen in C. ludioigii, C. stokesii, etc. The toe is 

 shortish, slender, with an expanded base and fine point. 



I can see no important difference between this and Mr. Harring's 

 examples. These often show a very minute shoulder, on the toe, 

 which is perhaps slightly longer. 



