NO. 1558. NORTH PACIFIC HOLOTHURIANS—fJDWARDS. 63 



the processes, terniiniil phites with tmnierous holes in several hiyers, 

 and net-like bodies with wide, irreg-ular meshes. 



Papillse. — Scattered small wheel-shaped plates and simple or 

 branched spinose supporting- rods, with some of the large wheels near 

 the tips. 



Tentacles. — Many of the large wdieels and small wheel-shaped plates 

 in the stalks, but in the disks only the last, together with crowded 

 spinose supporting rods. 



Calcareous ring. — Rudimentar}', fragile, spongy; its true form not 

 distinct. 



I\>Uan vesicles. — Two, each 20 nun. long, l.C mm. diameter, with a 

 common base for 'S mm. 



Stone canal. — Ends in dorsal madreporic papilla. 1 mm. in diameter, 



9 mm. posterior to the tentacles; a clear, slightly whitish, spherical 

 body, of no particular structure. 



Gonads. — On either side of dorsal mesentery one long (70 mm.) 

 tube, giving oti' richly branched lateral branches. The gonaduct opens 



10 mm. posterior to the tentacles. 



Comparative. — The one indi\'idual above extends the geographical 

 distribution of this species from one extreme of the Pacitic to the 

 other. From the three records now published, together with the 

 above description of the Alhatross specimen, it is difficult to say 

 whether there are several varieties of Theers type or just one very 

 variable species. The descriptions of PcutnycJiia nioseleyi Theel, 

 given by Theel, Sluiter, and myself, and of P. moseleyi var. henrice 

 Ludwig agree well enough and so intergrade as to constitute the one 

 species. Because of the inadequate description, the position of Pa)i- 

 oujchia icooiPniasoni Walsh, 1891, given by the author as closely allied 

 to P. moseleyi Theel is very uncertain, as both Ludwig (pp. 9.5-9(i) and 

 Sluiter (p. 72) have indicated. 



Ludwig established his variety upon the smaller number of pedicels 

 in the mid-ventral radius and the presence of three genital tubes, 

 instead of one, on each side of the dorsal mesentery. The number of 

 pedicels depends upon growth, although we have, as yet, no exact 

 formula for the determination of the age of a Holothurian. The size, 

 of course, in a general way gives some idea of age and maturity, as 

 Mitsukuri, 1903, found in the case of Stichopus jajxmicus Selenka, 

 and, as I have demonstrated in recent studies (1905), of Ilolothuria 

 floridana Pourtales and TI. atva Jaeger. 



While in general, as Ludwig suggests (p. 98), the number of append- 

 ages increases with size and age, yet my specimen, with a length 

 included in Ludwig's smallest class (66 to 175 nnu.), has a larger 

 number of lateral pedicels than even TheeFs type. The number of 

 mid-ventral pedicels in my specimen (24) agrees exactly with that of 

 Sluiter, and both are intermediate between Theel's type (55) and Lud- 



