68 PROCEEDINGS OF SOCIETIES. 



longer in the spines than is figured in the illustrative plate 

 accompanying M. de Brebisson's " Liste des Desmidiees observees 

 en Basse-Normandie ;" otherwise, however, agreeing therewith. 

 These examples were accompanied by St. defectum and St. ctispi- 

 datum, but always seemed quite distinguishable from both. This 

 belongs, indeed, to a group of nearly allied forms, which, although 

 they agreed essentially in outward characters, Mr. Archer ventured 

 to think seemed always readily distinguishable ; these are 

 Staurastrum apictdatum, St. dejectum, St. cuspidatum, St. Dichiei, 

 St. O'llearii, St. glahrum. 



Mr. Archer showed, new to Ireland, Spirofcenia minuta (Thuret); 

 this occurred near Carrig Mountain. 



Dr. Frazer showed a sublimate of arsenious acid in fine crystals 

 displaying interesting hemihedral forms. 



Dr. Frazer likewise, on the part of Mr. Woodworth, exhibited 

 specimens of human hair, now much sold in commerce for the 

 manufacture of chignons, as " Marseilles hair." This had the 

 hair-bulbs unremoved, and the enlargements had been imagined to 

 indicate the presence of " Gregarinse," but the microscope showed 

 their true nature. An interesting inquiry results as to the origin 

 of this kind of hair in commerce : it cannot be derived from living 

 human beings, for its removal in quantity by epilating would be 

 extremely painful, and, if obtained from the dead, it is probably 

 removed when putrefaction has set in. 



IQth September, 1867. 



Mr. Archer exhibited good recent specimens of the two little 

 algae lately recorded by him from Wales, then new to Britain, and 

 now for the first time discovered in Ireland — Dictyosphcerkini 

 reniforme (Bulnh.), and Cosmocladmm saasonictim (de Bary). 

 These specimens, which were from near Carrig Mountain, were 

 quite identical in every respect with those from AVales. For the 

 first record of these pretty little plants, see Club minutes of June 

 and July last. 



Rev. E. O'Meara showed a new species of Gephyria, of which 

 figures and descriptions will hereafter appear in this Journal. 



Mr. Archer also show^ed conjugated specimens, with the zygo- 

 spores, of Penium digitus (Ehr.), Breb.,now recorded for the first 

 time, commonly as this species presents itself. As, however, 

 might almost be predicated, the zygospore is simply large and 

 elliptic and smooth, being placed between the for some time per- 

 sistent empty parent cells, which are kept apart from the zygo- 

 spore by a conspicuous and thick gelatinous envelope. 



Mr. Archer drew attention to a form of Arcella agreeing with 

 Arcella angulata in surface characters of the test and in colour (no 

 foreign bodies whatever entered into its composition), but differing 

 in being of a quite globose form, with the exception of a small 

 chord, as it were, being cut ofi" at the aperture, in place of being 

 hemispherical or rather more or less broadly campanulate. Thus, 



