Cydostrema, Adeorbis, Vitrinella, and related genera. 141 



defined by an indistinct line. From this arise numerous raised lines 

 in the direction of the lines of growth, which are at first near 

 together but diverge toward the outer margin, where they terminate 

 just within the edge. Others arise between these about two-thirds 

 their length. 



Two large black eyes, close together on the top of the head, were 

 the only feature that could be discerned in the much dried animal, 

 the shell being removed by acid. The radula could not be found. 



Type, Cyclostremella humilis sp. no v. 

 Plate XXII. figs. 8-8Z). 



Shell minute, white, nearly smooth, consisting of two whorls, 

 besides the nucleus. Surface somewhat shining, but under the 

 microscope it is covered with rather conspicuous sinuous lines of 

 growth which are crossed on the peripheral region by several raised, 

 unequally separated, spiral threads, varying in number in difierent 

 specimens, so that in some they extend farther above and below than 

 in others. 



Diameter of one of the largest specimens, about 1-5™™ ; height, 

 about •7'"'". 



One live and several dead specimens at stations 2112, 2274, 2277, 

 2278, off Cape Hatteras, N. C in 15|-16 fathoms, 1883-1884. 



Lissospira profunda (Friele). See page 130. 



A specimen of Cyclosfrema proftcndmn sent to Professor Verrill 

 by Dr. Friele is much more transparent than any species from our 

 coast which has been referred to Lissospira. The three very con- 

 vex whorls form a small, elevated spire and abruptly enlarged body- 

 whorl. The nuclear whorl is smooth, below which the entire surface 

 is covered with numerous, raised, rather regular, evenly separated 

 spiral lines which, under the microscope, are crossed and inconspicu- 

 ously roughened by regular, raised, transverse lines which are more 

 evident on the interspaces ; the spiral sculpture becomes coarser on 

 the base. The umbilicus is of moderate size, deep. The aperture is 

 circular ; the peritreme is slightly injured but shows that it is con- 

 tinuous and slightly attached to the body -whorl. The operculum is 

 also typical. 



Greatest diameter, about 2 '5""" ; height the same. 



Yale University Museum, July, 1897. 



