478 University of California Publicatiovs in Zoology [Vol. 16 



its closer affinity to the Didemnidae through Trididemnum tliaii to the 

 Polycitoridae through Distaplia is undoubted. Having decided that 

 it belongs to the Didemnidae, the question as to what genus of that 

 family it should be assigned remains to be decided. Accepting the 

 genera of the family recognized by Hartmeyer (1909) only two of 

 the nine of these, Didemnum and Polysyncraton, are regularly char- 

 acterized by the possession of an atrial languet, and in both of these 

 the testis is single-lobed and the vas deferens is coiled ; so it does not 

 seem possible to regard our species as belonging to either of these 

 genera. All things considered, we conclude that the species can be 

 placed in Diplosomoides Herdman with less violence than in any other 

 recognized generic group. In all respects other than that of its atrial 

 lauguet, caullcryi conforms very well to the characterization of this 

 group; and we think Hartmeyer (1903) justified in redefining Diplo- 

 somoides as as to include species which, like his D. dubiiim, possess an 

 atrial languet. The languet of diihium is much shorter than that of 

 D. caullcryi, and the difference between the two' may be taken, as we 

 have contended in discussing the structure in Amaroucium, as indi- 

 cating its modernness and, perhaps for this reason, undependableness 

 for the characterization of genera. 



We take pleasure in naming this especially interesting species after 

 Professor Caullery, whose observations on the reproduction of various 

 species of the Didemnidae has contributed so much to our knowledge 

 of the remarkable plienomena here presented. 



Glossophorum planum, ii. sp. 



PI. 39, fig. l:;; pi. 4(3, fig. 71 



Superficial characteristics of the colony. — Larger colonies pumpkin- 

 seed shaped, smaller ones spherical, all having short, thick, cylindrical 

 penducles; outline regular, surface smooth, free from sand or other 

 foreign substances; systems distinct and regular, zooids plainly seen 

 through test; common eloacal orifices open and very distinct even in 

 preserved specimens (pi. 46, fig. 71). Color grayish brown, much the 

 same in living and preserved specimens. Length of about maximum- 

 sized colony 10 cm., width 5 em., thickness 1.5 cm. The test consist- 

 ing chiefly of a well-defined central core into which zooids do not 

 extend ; small in quantity among zooids ; matrix semicartilaginous and 

 transparent, but containing a great number of very small pigmented 

 cells which impart to it a somewhat dirty tinge; portions among 

 zooids containing scattered, rather small bladder cells ; central core 

 thickly penetrated by thin-walled transparent stolons to which zooids 

 are alwavs attached. 



