1892.] MlCilOSCOPlCAL JOURNAL. 253 



ture dealing with the DiatomacccE, as well as having made and 

 put upon record the largest single selected slide of diatoms from 

 a local circumscribed area, the same studied with a 1-15 homo- 

 geneous oil immersion lens of 1.25 N. A. in detail, as well as 

 microphotographed for permanent record, the slide being the 

 largest that has come under my notice, although larger and bet- 

 ter slides have been made by others, yet on a dissimilar plan, 

 and of course of greater perfection, merit, artistic skill, and 

 scientific value. 



To note additional devotion to the study, I may relate that I 

 have printed with pen and ink, in neat and legible italic letters, 

 the specific names of the 2,300 figures in my copy of WoUe's N. 

 A. Diatomaceae, contiguous to each species, v^^hich makes the 

 book doubly useful, as a glance at any plate dispenses with the 

 use of the numerical tables of species on the opposite pages. 



Finally, in treating of this science we must not overlook the 

 marvelous searching analybis of the diatomist, in the study and 

 preparation of material of low percentages, whose successful 

 manipulation aggregates, out of unpromising material, millions 

 of the beautiful frustules whose final function is to entrance the 

 eyes under the lenses of high or low power. 



Diatoms of the Connecticut Sliore. — III. 



By W. a. terry, 



BRISTOL, CONN. 



Among the new forms found at Morris Creek, and not men- 

 tioned in my former articles, are Tropidoneis (Plagiotropis) Zebra, 

 n. sp.,Cl. pi. xii,fig. 1, Le Diatomiste ; also Tropidoneis (Plagio- 

 tropis) seriata, n. sp., CI. pi. xii, fig. 2, 3, 4, Le Diatomiste. 

 This last form is very abundant in many of my gatherings from 

 the salt marshes, as is also Scoliopleura (Scoliotropis) latestriata 

 var. Amphora, n. var., CI. pi. xii, fig. 13, Le Diatomiste; other 

 new forms I defer mentioning until printed lists are received. 



The rocks near the tide gate at Alorris Creek are at some sea- 

 sons covered with a dense growth of filamentous diatoms, in 

 rounded masses resembling sponges in appearance, and of a light 

 yellowish brown colof. The filaments are from two inches in 

 length on the margins to four and six inches at the centre of the 

 masses, and are chiefly Melosira Borrerii, entangling many kinds 

 of the independent travellers, including fine specimens of Pleuro- 

 sigma Americanum and PI. paradoxum ; and here is a point which 

 I consider worthy of notice. We are told by some writers that all 

 diatom growth starts from a sporangial form, and that in multi- 

 plication by division each new valve is appreciably smaller than 

 the old one, and that the great difference in size found between 

 individuals of the same species is a result of repeated subdivision 

 and old age. 



