THE APODOUS HOLOTHUEIANS 25 



Labidoplax thomsonii (Herapath). 



A decalcified synaptid from Naples lacks sense-cups on the tentacles and 

 seems to be referable to this species. 



Pkotankyka abyssicola (Theel). 



Plate IV, Figs. 8-11. 



A single strongly contracted individual of this species is in the collection, 

 dredged by the "Albatross" in 2,260 m. (St. 2382) in the Gulf of Mexico, lat. 

 28° 19' 45" N., long. 88° 01' 30" W. Fortunately the anterior end is uninjured, 

 and it is possible, therefore, to figure one of the tentacles and the calcareous de- 

 posits. These agree essentially with those described by Ludwig ('94) for the 

 closely allied species pacifica. The specimen is 65 mm. long and 5 mm. in 

 diameter, and the color is dark yellowish, with considerable reddish pigment at 

 base of tentacles, on the inner side. Anchors and plates are numerous on the 

 bivium, but are almost wanting on the trivium near the middle of the body, 

 though somewhat more common posteriorly. There are 7 polian vessels, 

 slender and nearly equal. The stone canal was not found. The genital glands 

 are small and somewhat branched. The anchors (700 fi long) have the teeth 

 on the flukes sharp, and not blunt, as figured by Theel. The plates (550 z^) 

 have the holes rather smooth or with several teeth. No miliary granules were 

 found. 



Pkotankyka pacifica (Ludwig). 



The type and co-type of Ludwig 's Synapta abyssicola var. pacifica from 

 "Albatross" Stations 3360 and 3381, off Panama, 3,009-3,189 m., are in the col- 

 lection. They are quite diifereut from abyssicola and are entitled to full spe- 

 cific rank. 



Pkotankyka bkychia (Verrill). 

 Plate IV, Figs. 12-14. 



There is a single headless fragment of this species, from 1,688 m. off 

 Cape Hatteras ("Albatross" Station 2111), lat. 35° 9' 50" N., long. 74° 57' 40" 

 W. Although not labeled, I suspect this is VerrUl's type, as it is from the same 

 locality and answers his description exactly. It is gray, 100 mm. long and about 

 9 mm. in diameter. There are two polian vessels and long branched genital 

 glands. The anchors and plates are similar to those in the preceding species, but 

 are much larger, a full mm. or more in length, and the flukes of the anchors are 

 more slender. Miliary granules in the shape of simple elongated discs or oval 

 rods occur along the radii. The anchors and plates are in approximately three 

 longitudinal rows in each interradius. 



