222 DR. W. B. CARPENTEU. 



Color testas stellatae obscurus, griseo-brunneus, maculis 

 parvis flavo-brunneis spavsus^ iiiscqualibus, irregularibus, 

 paullumintentibus. Numerus denticulorum varians (10-15). 

 Diameter testae (sine dentic.) 5-6 mm. Longitudo denticu- 

 lorum 1-2 mm. 



The diameter of the central disk in the specimens sent me 

 by Prof. Loven commonly preaches one fifth of an inch, and 

 its radiating prolongations sometimes attain a nearly equal 

 length.' The test is essentially composed of sandy particles 



rof very irregular size and form, large rounded fragments 

 being occasionally interposed among the ordinary angular 

 grains, and the external surface being smoothed over by a 

 kind of plaster, which seems composed of particles of fine 

 mud, whilst the internal surface is roughened by the pro- 

 jection of angular sand-grains into the cavity^ as in Sacca- 

 mina (loo. cit.). These materials appear to be held together 

 by an organic cement, which imparts a certain degree of 

 flexibility to the envelope. The walls of the radiating 

 extensions are composed of small sand-grains embedded in 

 agglutinated mud, and the tubes thus formed are quite 

 flexible. 

 *•— -^ A few specimens were collected by Mr. H. Brady about 

 two years ago from the Dogger Bank, at depths of from 12 

 to 20 fathoms, which seem referable to this genus, though 

 difi"ering from Dr. Sandahl's type-form in some important 

 particulars. The lenticular disk attains in some specimens 

 a diameter of three tenths of an inch, but it is destitute of 

 radiating prolongations. The sand-grains, which (as in 

 Dr. Sandahl's specimens) are of very irregular size and 

 shape, seem to be more firmly united together ; but it still 

 appears probable, from the flexibility of the envelope they 

 form, that the uniting material is an organic, not a mineral 

 cement. The external surface (so far as can be judged from 

 specimens preserved dry) was not smoothed over by the 

 plaster, which concealed all but the largest sand-grains in 

 Dr. Sandahl's specimens. 



The Lightning dredgings at 170 fathoms (temp. 41 1°) in 

 the " cold area," and at 530 fathoms (temp. 48°) in the part 

 of the "wai-m area" most nearly approaching this, where 

 the Globigerina-mud was mingled with a considerable quantity 

 of the fine sand characteristic of its bottom, yielded a remark- 

 able series of arenaceous tests, presenting exactly the com- 

 position and mode of aggregation of the tests of the Lituohe 

 found in the same dredgings (loc. cit.), but exhibiting 

 singular diversities in form, some of the most remarkable of 

 which are represented in Plate XIX, figs. 1 — 13. \These 



