FROM NEW YORK, NEW JERSEY, AND GEORGIA, 151 



Oeniis Cyphoderia, Schlumberger. 



Cyphoderia ampulla {Elwenh.), Schlumh.^ 



C. margaritacea, Schlumb. 



Leidy, pi. 34. figs. 1-16 (30), 



Small and rather scarce, found only in the lakes and larger ponds ; it is 

 found in the New York City water-supply. 



Length 95-110 //,. Leidy gives the length as 110-200 yu, ; in the British 

 Isles the limits are 61-190 yu, (45). 



Distribution. North America. British Columbia (39), Colorado (35), 

 Florida (30), Iowa (21), New Jersey (30), Michigan (41), New York (20), 

 Nova Scotia (30), Pennsylvania (30), Rhode Island (30), Wyoming (30). 



C, TROCHUS var. amphoralis, Wailes (45). 



Of similar form to the preceding, but the test is composed of imbricated 

 plates instead of non-imbricated discs. Found in the same localities as the 

 preceding ; also in Long Island. 



Length 110-120 /*. Limits in Britain, 87-153 /i (45). 



A description and classification of this genus will be found in the Proc. 

 Hoyal Irish Academy, 1911 (45), from which it will be seen that, in the 

 absence of definite information as to the structure of the test {i. e, whether 

 imbricated or not), drawings of individuals cannot be identified. 



In the absence of this information some of Leidy's illustrations may 

 represent C. troclms or one of its varieties ; but taking for o-ranted that 

 all the tests are of the type shown in pi. 34. fig. 16 (30) — that is are 

 composed of round discs with a superficial hexagonal appearance — then 

 figs, 5-8 represent C. ampulla var, papillata, Wailes (45), a variety which 

 has been found in the Western States by Edmondson (private letter). 



C. ampulla var. major. Pen,, is also probably represented among Leidv's 

 illustrations, but cannot be identified without details of the structure of the 

 test (45). 



Genus Campascus, Leidy. 

 Campascus minutus, Penard. 



Occurs in the New York water-supply drawn from the Croton Lake 

 Reservoir, which is situated about 30 miles north of the city. 



This species has not been recorded previously from America, Length 

 64 yu, ; diameter 30 /i ; aperture 10 jx. 



Distribution. Switzerland [Penard) ; Loch Ness [Penard) and Hebrides, 

 Scotland. 



linn, JOURN, zoology, vol. XXXII, 13 



