234 Bulletin American Museum of Natural History. [Vol. XXXII, 



Stichopus parvimensis ! sp. nov. 



The specimens of this apparently new species agree with each other remarkably 

 well in all particulars. They are about 200 mm. long but pressure from each other and 

 from other specimens has so distorted them that their appearance in life is not easy 

 to infer. The pedicels are very numerous both dorsally and ventrally, and there is 

 no indication, even on the lower surface, of arrangement in longitudinal series. Along 

 each side of the body are a few (3-6) big tubercle-like papillae and there is at least 

 one row and probably two of similar papilla) on the back. Judging from other 

 species of the genus, the body in life is more or less quadrangular and there is a series 

 of these big papilla) along each angle. There are twenty tentacles. The calcareous 

 ring is well-developed and not peculiar. The gonads are in large equal tufts, one 

 on each side of the dorsal mesentery. The color is light chestnut-brown, much paler 

 below than above. Most of the pedicels, but not all, are very dark brown, and thus 

 appear in the preserved specimens like small blackish spots. 



The really characteristic feature of this species is to be found in the calcareous 

 deposits. Like its previously-known fellow species of the Pacific coast of America, 

 this new form has both "tables" and "buttons" in the body-wall. The buttons are 

 about 90 yu in length and have three or four pairs of holes. They are not usually very 

 symmetrical and hardly any two are exactly alike. As compared with the buttons 

 of S. californicus and S. johnsoni, these deposits are very small and have a small 

 number of holes, for in californicus, the buttons are 140-165 n long and have fre- 

 quently 10-12 holes, while in johnsoni, the buttons are 165-190 n in length with 

 10-16 holes. Similar peculiarities mark the tables; in parvimensis, the disk is only 

 about 45 ix across and rarely has more than four perforations, though occasionally 

 two or three other small ones alternate externally with the primary ones; the crown 

 of the spire has 8-10 teeth and is less than 20 n across. In californicus, the tables 

 are larger and more variable, the disk measuring from 50 to 90/x in diameter and 

 having 8 to 18 perforations, while the spire is crowned with 12 or more teeth and 

 measures about 25 m across. In johnsoni, the tables are again much larger, 120-170 n 

 in diameter with 25-40 holes in the disk and the spire with 20-25 teeth on the crown 

 which is nearly 50 ju across. 



Type.— Cat. No. , U. S. N. M. 



It is curious and a little perplexing that johnsoni which is geographically 

 intermediate between the other two species is not so structurally but has 

 the most highly specialized calcareous particles. Of course, it may be that 

 we shall find the three species have broadly overlapping ranges and future 

 study made show that all are forms of a single variable species. But I have 

 compared the specimens of parvimensis before me with the type of Theel's 

 species {johnsoni) and with specimens of californicus from Monterey Bay, 

 California, and from Puget Sound, and I find no reason whatever for not 

 recognizing each as a valid species. 



The label with the three specimens of parvimensis says they were taken 



1 parvimensis = with small tables. 



