i62 REPORT OF NEW JERSEY STATE MUSEUM. 



basal diameter of shell. Radii rather narrow, deeply depressed, 

 their summits square and outer lamina on both sides of each 

 suture usually divided into teeth, points of which face and touch 

 each other. These teeth give quite peculiar appearance to shell, 

 sometimes blunt and partially obliterated. Occasionally all six 

 radii perfectly smooth. Radiating" parietal septa and de- 

 scending sheath thick, their basal edges plainly seen by 

 naked eye to be dentated with numerous points. Thickness of 

 these plates and sheath varies considerably. Descending 

 sheath not generally perforated, except at sutures by loop- 

 holes for entrance of ribbons of corium. Sheath and inner 

 lamina of parietes together fully equal one-third entire thick- 

 ness of walls. Flattened cavities or tubes run up between 

 parietal septa about two-thirds height of inside of shell. Thick- 

 ness of inner portion of radii varies considerably to generally 

 notched outer lamina. Scutum with occludent edg'e always 

 sinuous, though variable. Terga vary, according to more or less 

 truncated basi-carinal corner. External furrow, marking posi- 

 tion of rudimentary spur, varies in distinctness, chiefly depend- 

 ing upon its nearness to carinal edge of valve. Labrum of 

 mouth sometimes has its teeth worn away. Second pair of 

 cirri relatively shorter and thicker to others. Length 0.55 inches, 

 basal diameter 2.3 inches. (Darwin.) 



Remarks. — -I have examined se\'eral examples from Point 

 Pleasant, secured by Mr. Witmer Stone. This species occurs 

 on our large sea turtles. Doubtless a large loggerhead (Caretta 

 carctta) taken in Delaware Bay near Green Creek several years 

 ago and found more or less covered with rounded plate-like and 

 other barnacles, belonged largely to this species. Mr. H. W. 

 Hand, who gives this information, says the turtle was easily 

 captured. After removing the barnacles and giving a coat of 

 copper paint over the carapace, the liberated turtle swam away 

 with apparent relief. 



The species does not appear to have ever been recorded from 

 New Jersey previously. It is known from the Mediterranean, 

 west Africa, northeast coast of Australia, the low Archipelago 

 and the Pacific Ocean. It is found attached to large sea-turtles. 



