62 



SCIENCE. 



[N. S. Vol. XV. No. 367. 



larger-sized individuals, are the characters 

 usually distinctive of A. erinaceus.. But 

 these all fail to furnish differential marks 

 for many specimens. 



With these two forms, contrary to what 

 we find in Toxopneustes, hathymetric range 

 appears to play no part, as they occur to- 

 gether everywhere in from eight to ten 

 fathoms, to the greatest depths reached 

 in our work. We have thus far been un- 

 able to correlate these two varieties with 

 any environmental peculiarities whatever. 

 The general distribution of these two 

 species, as contrasted with the restricted 

 distribution of some other species of both 

 Echinoids and Asteroids in this locality, is 

 noteworthy and is all the more interesting 

 when the variability— as contrasted with 

 the lack of variability in other species 

 localized in their distribution— is regarded. 

 Mediaster ceqiialis Verrill, for example, 

 may be cited as a species of great rigidity 

 in tj^e. The individuals of this species 

 all have the appearance of having been cut 

 out by the same die, so alike are they in 

 form ; and having been dipped in the same 

 paint-box, so similar are they in color. 

 This species was taken at only two or three 

 stations, and in any abimdance at only one. 

 Such facts as these strongly impress 

 one who comes face to face with them 

 with the scantiness of our knowledge of 

 the deeper meaning of the relation of 

 organisms to their environment. 



Miss Monk's studies on Phataria, a star- 

 fish remarkable even among its close allies 

 within the family Linckiidse, for the vari- 

 ability in the number of its rays, and the 

 readiness with which it parts with them 

 and then regenerates them, led to the fol- 

 lowing results : 



1. The observations proved conclu- 

 sively that the casting off of the rays is, in 

 most cases at least, not accidental, hut a 

 true self-amputation. 



2. As the breakage usually occurs at 



some distance from the disk, and as the 

 ' comet ' stars are found abundant in 

 nature, it appears as though the autotomy 

 is for the purpose of asexual reproduction, 

 and hence that the severed arm to which 

 no part of the disk adheres has the power 

 of reproducing the entire animal. But ab- 

 solute certainty on this point is still to be 

 reached. 



A species of Antedon closely related to, 

 if not identical with, A. rosacea was taken 

 off San Diego in about one hundred 

 fathoms. So far as I am aware, this is 

 the first record of the occurrence of any 

 species of this genus on the Pacific coast 

 north of Panama. 



B7-yosoa.— Under the name of Ascorhiza 

 Calif ornica, Dr. Walter Fewkes described 

 a new genus and species of Bryozoan 

 dredged by him in Santa Barbara channel 

 in 1886. The colony consisted of a well- 

 defined capitulum, to which the polypides 

 are restricted, and a long, slender, flexible 

 stem. From the general resemblance of 

 the stem to that of Urnatella, the author 

 surmised the species to be related to the 

 Endoprocta. In the capitulum, however, 

 he recognized some resemblance to Alcyo-. 

 nidium. He, consequently, suggested that 

 the form might stand intermediate between 

 the Endoprocta and the Ectoprocta. As 

 he did not, however, make out much about 

 the polypides, he was unable to support the 

 suggestion with much evidence. 



Several specimens of this unique species 

 were dredged during the summer, and 

 from these Miss Alice Robertson has been 

 able to establish definitely that its affinities 

 are undoubtedly mth Alcyonidium, and 

 that its resemblances to Urnatella are wholly 

 superficial. It is, nevertheless, a very in- 

 teresting form, especially in the nature of 

 the stem. Miss Robertson will shortly pub- 

 lish a paper on this and one or two other 

 species of Alcyonidium of the Pacific coast. 



A noteworthy fact in connection with the 



