296 Transactions. — Botany. 



9. Scenedesmus quadricaiida, E., xxxi. 

 ,, obliquuSfB.., xxxi. 



,, obtusus, E., xxxi. 



I have included the Pediastrecp. in this family for the sake of convenience, 

 although the definition of the Desmids as given by both Hassall and Ealfs 

 would exclude them, and Carpenter arranges them as a separate family. 

 (When this paper was read I had not seen Mr. Maskell's article on the 

 DesmidiacecB of Canterbury.* Since then I have considerably modified my 

 remarks on this family, in order to avoid useless repetition and to bring 

 it as far as possible into accordance with Mr. Maskell's paper). 



Micrasterias ampullacea, var. (a) from Euataniwha. 



,, ,, var. (/3) Euataniwha. This plant resembles var. 



/3, in general outline, but differs in the smoothness of the edges of the fronds, 

 in the flatness of the tips of the segments of the lobes, and in the absence 

 of punct^e inside the margins of the frond. The flask-like shape of the 

 segments is very marked. I have placed it under the head of M. ampullacea, 

 var. /3, for the present, but I am not sure that it will remain there per- 

 manently. Fig. 6. 



Cosniarium cucumis ? I have marked this with a note of interrogation, 

 because I have seen only one specimen. It corresponds, however, so entirely 

 with Ealfs' description in the smoothness of the frond, the deep constriction, 

 and the equality of length and breadth, and the rotundity of the ends of 

 the segments, that I have httle doubt as to its identity. 



Cosmarium tetraophthalmium is common. 

 ,, margaritiferum abundant. 



,, sp. n. Frond quadrate, slightly longer than broad, not 

 deeply constricted. Segments conical truncated, united at the truncations, 

 edges smooth. End view circular. This plant is remarkable for its pecuHar 

 hour-glass shape. I have found no description of anything like it in such 

 books as have been accessible to me. If it prove a new species I should pro- 

 pose the name of C. clepshydra. Fig 7. 



Staurastrum, sp. ? Edges of frond smooth, segments united below, 

 divaricating. Upper and outer borders concave, uniting at an acute angle, 

 inner slightly convex, lower rounded. On the upper concave border are 

 three hyaline processes with smooth sides and flattened ends. At junction 

 of outer and lower borders is one process similar to the upper ones but 

 curved slightly outwards. This little plant is unlike anything in Ealfs — 

 it might be an unusual form of S. lave, but in the latter the processes are 

 forked, in the former not. Fig. 8. 



Closterium. In this genus I have not found any specimen that could not 

 be referred to Ealfs. 



* Trans. N.Z. Inst., vol. xiii., art. xxxviii., pp. 297 — 317. 



