Victorian Rotifers. 57 



minent anterior and posterior spines differed in length and 

 curvature, but not to the extent found in some other species of 

 the genus. The dimensions of the specimens were : — Length 

 of lorica, without spines, 0.15 mm.; total length, 0.45 mm.; 

 breadth, 0.15 mm. 



B. angularis, Gosse. The forms found vary from the figures 

 given in '' The Kotifera." A comparison made between actual 

 specimens may establish a variety. The points of agreement 

 are, however, such as to suggest that the discrepancies may be 

 due to inadequate figuring of the European specimens. 



B. lyratus, n.sp. (Plate XXL, figs. 5 and 6) Templestowe and 

 Black Rock. This form, viewed on the dorsal surface, is of ovate 

 outline, swelling towards the lumbar region. At the anterior two 

 short outwardly curved spines are placed on either side 

 of a notch occupied by a well-developed dorsal antenna, and 

 on each side of these spines there is a pair of slight acute 

 prominences. At the posterior end there is a deep, squarish 

 recess, made deeper by two knobbed projections which curve 

 outwards in a manner suggesting the form of a lyre. A lateral 

 view shows the lorica to be arched dorsally, being highest 

 towards the posterior end ; the ventral surface is flat. Viewed 

 ventrally the lorica possesses a wavy outline at the anterior, 

 with two lines running backwards and inwards on either side. 

 These two lines are, I believe, a view of the edges of two trian- 

 gular plates so placed as to cause the lorica to gape and thus 

 form an opening for the protrusion of the corona ; whether 

 these plates are flexible, and thus permit of closure of the open- 

 ing, was not determined. The animal is of a pale brownish 

 colour. The lorica is covered with minute papillae, and is 

 indistinctly faceted. The small limibar antennae occur in the 

 usual position. The corona, foot, mast ax, eye and internal 

 structure generally present the characters usual in the genus. 

 Dimensions: — Length of lorica, 0.16 mm.; breadth, 0.135 mm. 

 Heidelberg. 



B. dichotomus, n.sp. (Plate XXIL, flgs. 3 and 4). This 

 form WHS met with in the same gathering as B. Jyvatus. 

 Dorsally, the lorica presents a somewhat ovate shape, 

 truncated anteriorly and provided with two hmg spines 

 branching outwards so as to form a V-sliaped notch between 



