76 THE NAUTILUS. 



Caecum auriculatum de Folin. PI. \\ Fig. 4. 

 A number of specimens in the collection resemble the figure 

 of this species as given by Try on. The shell is thin, white, 

 hyaline, very narrow for its length, faintly enlarging toward the 

 aperture. Near the aperture faint lines of growth are seen. 

 The septum is distinctly hemispherical or mammillate. 



Caecum clarkil Carpenter. PL V, Fig. 5. 

 A number of these glassy tubes were found identical in shape 

 to C. auriculatum but only half the size. It cannot be an early 

 deciduous stage because the diameter of the tube is much 

 smaller. C. clarkii as figured by Tryon bears some resemblance 

 to this form. It has the same hemispherical septum. The 

 operculum is light corneous in color, flat with a central smooth 

 area with a distinct knob in the centre; this area surrounded by 

 minute lines of growth. The form approaches C. cornubovis of 

 Carpenter. 



Caecum nitidum Stimpson. PI. V, Fig. 6. 

 This form of which a number of specimens were found is 

 without question Stimpson' s species described as a Florida 

 shell. 



Meioceroi &\i.^ Carpenter. PI. V, Fig. 7. 



Two specimens in the collection are identical with the figure 

 given by Tryon. Its distribution is given from Florida to Rio 

 de la Plata. 



Stimpson described under the name of pulchellum the first 

 Caecum discovered on the New England coast and gives an ex- 

 cellent figure of it in his " Shells of New England." The species 

 was dredged in ten fathoms of water in New Bedford harbor. 

 The other two species of New England Caecum were also found 

 south of Cape Cod. By far the larger number of Caecum col- 

 lected at Easton's Beach consisted of C. pulchellum. Miss M. 

 W. Brooks also collected a number of Caecum at Narragansett 

 Pier and most of these were C. pulchellitm. The shell is light 

 horn color and easily distinguished. The second deciduous 

 stage of pulchellum was very common in the collection. The 

 shell enlarges quite rapidly towards the aperture and is more 



