1894.] MICROSCOPICAL JOURNAL. 81 



Near the R. R. station at Leete's Island is a small fresh- 

 water pond used as an ice pond, whose bed was once a 

 salt marsh ; in this pond I found abundance of living spe- 

 cimens of a small Pleurosigrna I had never met with be- 

 fore, Pleurosigma subsalinum. The valves of this spe- 

 cies are so exceedingly light and delicate as to be nearly 

 invisible, and I might not have seen it if 1 had not found 

 it living ; the median line has a peculiar bend resembling 

 a sickle. Dr. Ward writes : "You are undoubtedly right 

 in naming the Pleurosigma F. subsalinum.'" It belongs to 

 Peragallo's eighth group, but the markings are finer than 

 those he gives, I had diflBculty in resolving the longitudi- 

 nal lines with a good homo immersion 1-12 (Reichart) by 

 central light, though they came out well by oblique il- 

 lumination." He adds, "the Beatties Pond slide is one 

 of the most interesting I have seen for a long time, I 

 looked it over last night and made a list of the forms I 

 found. There are a good many others I coiild not name 

 off hand, and several which are new to me, I found doz- 

 ens if not hundreds of Namcula peripunctata, Brun. (Esp. 

 Nuov. PI. XVI, Fig. 11). Brun gives Crane Pond as the 

 source of his original specimen. I found Navicula peri- 

 pufictata, viridis, peregrina, snnthii, i^iterrupta, limosa, «.s- 

 tuarii (Cleve), cri'ssinerm<i, nobilis, delaicurensis ,forinosa , 

 gibba, producta, elegaua, major, borealis, ligumen, etc; Nitz- 

 schia tryblionella, (2 var.) plana, scalaris and obtusa ; Su- 

 rirella gracilis ; S. {tenera var ?) terryana : Achnan- 

 thes subsessilis, Coconenia scutellum ; Pleurosigma affine; 

 Cyclotella striata: Strauroneis gracilis ; Eunotia major and 

 arcus ; Gomphonema. accuminatum ; Raphoneis aitiphice- 

 ros; Amphiprora lepidoptera ; Van heurckia rhomboides 

 var.,* amphipleuroides ; Tabellaria fenestrata ; Syiiedra 

 pidchella;Coscinodiscus excentrieus ; Actinoptychus undu- 

 latus ; Mastogloia a/igidata." 



I have the Crane Pond material to which Brun credits 

 his specimen, but the Beattie's Pond material has hun- 



