98 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Outer surface very variable in character, often merely deeply and 

 irregularly wrinkled and furrowed, but in most of the specimens a 

 greater or less part of the body, especially in the dorsal and anterior 

 regions, is covered with low flattened rounded elevations separated 

 by narrow shallow furrows, giving the surface more or less the 

 appearance of a cobblestone pavement. One large specimen (from 

 station D5218), which is very irregular in form with a deeply and 

 irregularly wrinkled surface, but is apparently of this species, meas- 

 ured about 78 mm. long by 44 mm. in height, exclusive of the processes 

 for attachment. The other specimens are all considerably smaller, 

 the largest 55 mm. long by 28 mm. high, exclusive of the pedicel and 

 the papilla bearing the atrial orifice. 



The mantle and internal tissues have a dark brown color, as in 

 P. aurata described above, and the internal structure is so similar 

 to that species that a separate description, other than a mention of 

 certain small differences, will be needless. 



The dorsal tubercle, though of similar structure, usually has more 

 numerous and more minute apertures, giving its surface a spongy 

 appearance. 



Internal longitudinal vessels more numerous. In one of the large 

 specimens their distribution is about as follows on the right side of 

 the body : 



dorsal 9 (24) 8 (22) 8 (25) 6 (19) 6 ventral. 



They are separated by narrower intervals and fewer stigmata, only 

 3 or 4 on the intervals between folds in the dorsal region, and usually 

 not over 5 or 6 in most parts of the ventral region except close to the 

 endostyle. 



Intestinal loop proportionately broad; there is usually practically 

 no forwardly extending terminal section or rectum, the intestine 

 making only a slight forward bend just before its termination, which 

 is in a many-lobed orifice. 



Gonads elongated branching tubes more or less confluent to an 

 irregular network covering a large area on the right side and a 

 smaller area (anterior to the intestinal loop) on the left side. Their 

 branches often appear to anastomose so as to form meshes inclosed on 

 all sides. 



Localities of the specimens (one specimen from each) : 



No. 97. Station D521S (between Burias mid Luzon, near Anima, Sola 

 Island, 20 fathoms, coarse sand, Apr. 22, 190S). Very large, 

 irregularly shaped specimen (Cat. No. 6019, U.S.N.M.). 



No. 149. Station D5251 (off Linao Point, Gulf of Davao, 20 fathoms, coral, 

 May 18, 1908.) (Cat. No. 6011, U.S.N.M.) 



No. 158. Station Dr>2~>0 (near the last, 23 fathoms, coral sand, May 18, 1908). 

 (Cat. No. G010, U.S.N.M.) 



No.no. Station D5253 (near the last. 28 fathoms, coral, May 18, 1908). 

 (Cat. No. 6012, U.S.N.M.) 



