20 BUOOKLVN INSTITUTi; MUSEUM. SCIENCE BULLETIN 2. 2. 
water over the gill, the mantle margin with its row of minute fleshy 
points showing beneath it. One animal crawled up the side of the 
aquarium two or three inches above the water and rested there several 
hours. 
The jaws and radula are kept in constant motion, the mouth dilating 
and contracting in rhythm with the radula which runs forward with a 
decided stroke, then returns and again advances. These movements 
are easily observed as the animal crawls over the side of the jar, or 
still better, on a piece of window-glass held in the hand. 
According to Morse A. testudinaUs is sluggish in habits, occurs in 
pools at low tide exposed to dashing waves, remains fi.xed for hours : 
and he says : "and only in the extreme young have I seen considerable 
freedom of motion." 
Not being able to obtain the animal of the large .icmaca from 
Maine, my comparisons are based upon the shells, and upon the papers 
by Jackson, Morse and Wilcox. 
The name is for the late David W. Ferguson ( Nautilus XNH, 1909. 
p. 124) who, according to Smith and Prime, found the shell at Glencove. 
Long Island, prior to 1870. 
BlHEIDGRAI'ITV. 
Jackson: The differences between the two New England species of 
z\cmaea. Nautilus. XXI, 1907, pp. 1-5. 
Wilcox: Anatomy of Acmaea tcstudiiialis. Amer. Nat. XXXIX, 
1905. pp. 325-333; XL. 1906, pp. I7I-I87. ^ ,. TT- 
Morse: An early stage of Acmaea, Proc. Boston hoc. Xat. Hist., 
34. 1910- I'P- 313-323- 
Urosalpinx cinerea var aitkinae var. nov. 
Shell differing from typical U. cincrca in color which is pure 
white or rarely with a pale flesh tint within. Two of ten specimens are 
faintly tinted;' the others are all glistening white within, and of a dead 
white on the rough exterior. Animal not observed. 
Tvpes from rocks in Hempstead Bay. Long Island, June 2~. 1913. 
found 'living by Miss Helen J. Aitkin of the Central Museum, in the 
Museum of The Brooklyn Institute, Accession No. 12657. 
Other specimens taken in the same locality are dark purple within, 
the majority of them spirally banded, having two yellowish zones se]ia- 
rating the jiurple into three zones one of which is peripheral. 
