106 THE AMERICAN MONTHLY [June, 



The pools that are so frequent upon the vast meadows that lie between 

 Atlantic City and the mainland are also excellent collecting places. On 

 sunny days the surface of these pools is often almost covered with diatoms. 

 Scoliopleura Uiinida a.n(X Pleurosi^tna Balticum may often be obtained here 

 in great quantity. Other species of Pleurosig7na and Amphiprora pulchra 

 are not uncommon. In visiting these pools it is best to leave the train at 

 Absecon station and visit those nearest the mainland, as those near Atlantic 

 Citv are much contaminated with sewage. 



In the brackish ditches the curious and ever interesting Bacillaria pa^-a- 

 doxa may often be obtained in abundance, sometimes clinging to the stems 

 of water plants, but oftener in little patclies upon the surface of the water. 



Appended is a list of the species observed mostly during the spring and 

 autumn months : 



IN THE MEADOW-POOLS NEAR THE INLET. 



Amphora costata, Gregory, A. lanceolata^ Cleve, A. lineata^ Greg., A. 

 pli'cata, Greg., A. rectatigularis, Greg. ; BiddulpJiia rhofnbus^ W. Smith ; 

 Coscinodisctis o77iphalanthus ^ Ehrenberg, C. eccentrictis. Ehr., C. lineatus^ 

 Ehr. ; Epithe7nia mtisculus,YM.\.x\\\'g\ Navicula a/72p/iisbce7za^ Bory, A^. 

 peregritta^ Ehr.. A^. per77iag7ia. Bailey, JV. p/'cetexta, Ehr., N'. veneta^ 

 Kutz. ; AHtzschia bilobata^ W. Sm., N. Epithe77iioides^ Brebisson, N. 

 77ia7'i7ia, Grunow, N. Szg77ia, W. Sm., A^. vivax^ W. Sm. : PIeu7-os/gma 

 Baltifti77t^ W. Sm. ; P.fasciola. W. Sm. ; Rhapho7ieis a77ip/iice7-os. Ehr. ; 

 Scoliopleu7-a tu777ida. Rabenhorst ; Stauro7ieis aspera. Ehr. ; T}-icei-atin77i 

 aHer7ia7is^ Bailey, T.favus^ Ehr. 



ON ALG.« IN THE BAY. 



Ach7ia7ithes b7'evipes. Agardh ; Berkleya fras^ilis^ Greville ; Biddiclp/iia 

 aurita^ Breb., B. Icevis. Ehr., B . pidchella^ Gray; Cocco7teis scutellum^ 

 Ehr.; G7'a77777iatopho7'a md/'ifta^ Kutz.; LiC77iopkora Jlabellata, Ag.^ L. 

 tincta., Grun. ; MeIosi/-a fiu77i77i7(loides^ Kutz. ; Rhabdo7ie77ia Adriaticu77i ^ 

 Kutz., R. arc7tat7i77i^ Kutz. ; Schizo7ie77ia A77ie/-ica7ii(77i^ Grun., S. G/'e- 

 villii^ Ag.; Stz-iatella ti/iipimctata^ Ag. ; Sy7iedra fulgeTis^ W. Sm. 



IN POOLS ON THE MARSHES NEAR THE MAINLAND. 



Amphtprora pulc/ira,^ai\e\ \ BaciJlaria paradoxa^ Gmelin ; Melosi7-a 

 7iu7nmuloides. Kutz. ; PIeiu-osig7)ia Balticum^ W. Sm., P. fasciola^ W. 

 Sm., P. hippoca77ipus^ W. Sm. 



IN BRACKISH DITCHES AND MARSHES NEAR ABSECON. 



Acti7ioptvchtis 7i7idulatt(s. Ehr.: A77ip/iiprora pulcJii'a^ W. Sm. ; Coc- 

 co7ieis sc7/teIhi77i,YA-\r. ; Coschzodisczts s?ibtilis^Yjhr. ; Cyclotella ope7'Czilata^ 

 Kutz. ; Naviczda elega7is^^ . Sm., N. didy77za, Kutz., N. peregrizza^ Ehr., 

 N. puszlla, W. Sm., N. S77zitJzii, Breb., N. forcipata, Grev. ; Nztzschia 

 dubia, W. Sm., N.fasciczdata, Grun., N'. grazzzdata, Grun.,^V. Scalaris, 

 W. Sm., N. Sig77za (W. Sm.) var. rzgzdzda, Grun. ; Rhaphozzezs a77zphz- 

 ceros, Ehr. ; RJzozcospJzenia curvata, Grun. ; Stauroneis salz7za.\N. Sm., 

 SurireUa arzgzista, Kutz. ; 6". Pebz'gerrz\ Lewis, S. ge77Z77ia, Ehr., S. 

 MoUeriazza, Grun., 6". ovata. Kutz. ; Trybliozzeda levzdezzsls, W. Sm. 



Micromillimeter. — A recent article m JVatzire speaks of the value of the 

 micromillimeter which obtains among microscopical writers as a thousand 

 times larger than the value of the same unit given it in the writings of phys- 

 icists and accepted as authorities by a commission of the British Association. 

 A micromillimeter has thus two meanings : — a thousandth of a millimeter 

 and a millionth of a millimeter. It is suggested by Mr. A. W. Riicker that 

 the botanists adopt the term 77zzcro77zetre, to stand for the thousandth of a 

 millimeter. He recognizes its similarity to 77zzcro77zeter as the name of an 

 instrument, but does not consider this a valid objection to its adoption. 



