40 



THE AMERICAN MONTHLY. 



[February. 



cover is pressed down, requiring no fur- 

 thur leveling. Place two drops of the 

 mixture in a cell so that it may be a little 

 more than full when the cover is applied 

 to avoid air bubbles, ring with white zinc, 

 first tacking the edges of the cover to 

 avoid moving it with the brush. 



A. G. Field. 



Pteratomus Phaseolus. 



To THE Editor : — In the month of Oc- 

 tober last, while examining the pollen of 

 flowering bean {Phaseohis tnultiflorus), I 

 discovered a hymenopterous insect which 

 appeared to be feeding upon the pollen 

 grains. As far as I can discover, this is 

 hitherto undescribed. It belongs to the 

 genus Pteratomus. 1 propose for it the 

 name of Pteratomus phaseolus, and sub- 

 mit the following description : 



Order Hymenoptera. Family Procto- 

 trtipii, Lat. 



Pteratomus phaseolus, n. s. ? 



^ 9 Total length ^^-inch, breadth )/% of 

 length. Antennae 6-jointed. The 5 basal 

 joints each armed with a short spine. 

 Joints similar except terminal, which swells 

 slightly before tapering to point. Head 

 and thorax armed with a few stiff spines. 

 Abdomen about 3 times length of thorax, 

 about same breadth, with stiff hairs from 

 each segment. Clearly divided into seven 

 segments of about equal length, except 

 anterior, which is about one and one-half 

 times the length of the others, having 

 two rows of spines. Legs armed with a 

 spine on last joint. Wings transparent, 

 fringed, and covered with minute hairs. 

 Color uniformly ochreous brown. Eyes 

 large and black. The anal claspers of 

 male very large, much serrated. Habi- 

 tat — flower of bean. Larval stages un- 

 known. October. 



Jno. B. Betts. 

 Camden, N. J. 



Photo- Micrography. 



To THE Editor : — I have become quite 

 interested in the subject of photo-micro- 

 scopy ; but I know nothing of the relative 

 value of the various instruments on the 

 market. I should be glad to see in your 

 paper a review of the different apparatus. 

 I think this would come in very oppor- 

 tune, as there are to be papers on photo- 

 graphic methods. 



[We shall have something to say upon 

 this subject before long, if we are not an- 

 ticipated by some contributor who will 

 favor us with his experience. It is a sub- 



ject of growing importance ; and we would 

 be glad to receive an article upon the 

 apparatus offered by various makers. — 

 Ed.] 



Spongilla. 

 To THE Editor: — That fresh-water 

 sponge motmt now on its travels in the 

 postal club boxes,' which you kindly 

 noticed, was labeled Spoftgilla, not to in- 

 dicate the genus, but simply because the 

 term, by common consent, means a fresh- 

 water sponge. As it may interest those 

 who have seen the mount, and those who 

 will see it, to know the correct name, I 

 would like to say it is Hcteromeyetiia 

 Rideri, it having been determined by Ed- 

 ward Potts, the able specialist. 



S. LOCKWOOD. 



December 20th, 1884. 



NOTICES OF BOOKS. 



Ceratiocarida: from the Chemung and 

 Waverly Groupfs at Warren, Pennsyl- 

 vania. By Chas. E. Beecher. With 

 two plates. Harrisburg: Lane S. Hart, 

 Printer. 1884. (Pamphlet, pp. 24.) 



The Fresh- Water Flora and Fauna of 

 Central Park. Preliminary paper, with 

 bibliography. By L. P. Gratacap and 

 A. Woodward. New York : Macgowan 

 & Slipper, Printers. I884. (Pamphlet, 

 pp. 19.) 



This is a useful, although, being a pre- 

 liminary paper, not by any means a com- 

 plete, record of the fauna and flora of the 

 lakes in Central Park, New York. A list 

 of organisms found is given, and a 'Con- 

 tribution to the bibliography of fresh- 

 water flora and fauna of the United States, 

 mostly microscopical,' which covers seve- 

 ral pages. Doubtless the pamphlet can 

 be obtained by addressing Mr. Wood- 

 ward, at the Museum of Natural History, 

 New York City. 



Exchanges. 



[Exchanges are inserted in this column without 

 charge. They will be strictly limited to mounted ob- 

 jects, and material for mounting] 



Exchanges by list of all kinds of first-class material 

 for mounting solicited. A. M BOOTH, 



Longmeadow, Mass. 



Unmounted material and labels for slides in ex- 

 change (or good slides. 



EUGENE PINCKNEY, 



Dixon, III. 



Fossil Diatomaceous Earth, (a new find), very inter- 

 esting forms for other material. 



J. WALKER, 

 810 Twelfth Ave., South Minneapolis, Minn. 



