01' THE TERPSINOEiE. 



859 



external resemblance of their solitary frustiiles, we believe them to differ 

 essentially in structure. In StriatelleaB the septa are longitudinal, and divide 

 the central portion into chambers. In Terpsinoe86 they are transverse and 

 confined to the lateral portions, which appear in the front view as in Biddul- 

 phiese. The relation of Terpsinoeas to the latter was pointed out by Mcne- 

 ghini. The smooth frustules and straight lateral margins without processes 

 distinguish the Terpsinoeae. 



Genus ANAULrS (Ehr.). — Frustules simple, subquadrate, smooth ; septa 

 lateral, unequal, not thickened at their extremities; lateral view oblong, 

 Anaiilus resembles Biddulphia, but its costae or septa are unequal, and it has 

 no tubular processes. A genus of Mollusks has been also, but more recently, 

 called Anauius. 



Anaulus scalaris (E.). — Tm-gid in 

 the young state; but when full-grown 

 very wide and much flattened, having 

 4, 6, 8, or 14 lateral constrictions ; late- 

 rally oblong with transverse bars, giving 

 it a ladder-like appearance. EM. pi. 35 a. 

 22. I 1, 2. Antarctic Sea. Diam. 1-480" 

 to 1-180". The lateral valves, in the 

 front view, have undidated margins, 



caused by the constrictions, (viii. 37.) 



A. Campijlodiscus (E.). — Quadrangu- 

 lar ; each valve very much compressed, 

 triangular, with obtuse angles, and hav- 

 ing laterally two slight constrictions. 

 Bermuda. Diam. 1-372". It has the 

 habit of an unequal-sided Triceratium or 

 of a Campylodiscus. 



Genus TERPSINOE (Ehr.). — Frustules concatenate; cost« unequal, capi- 

 tate, cuiwed so as to resemble musical notes. " If we imagine a series of 

 frastules of Tabellaria joined together, not laterally, but the head of one to 

 that of another, or in the direction of breadth instead of length, we shall 

 form the most just idea of this genus " (Ehr.). The capitate costae, which 

 in their form so greatly resemble musical notes, distinguish Terpsinoe from 

 every other genus. 



We unite Tetragramma with Terpsinoe, as Professor Bailey finds the 

 " music-hke notes" vary in nimiber from two to at least eight on a side, 

 and does not consider theu- number even specifically important. 



Tehpsinoe miisica (E.). — Frustules 

 finely punctated, with two or three trans- 

 verse bands, the lateral valves having 

 costae in each division ; lateral view ob- 

 long, showing two or three infiations and 

 narrower rounded ends. EA. pi. 3. 4. £ 1 ; 

 liab D. 1. 10. America, Africa, (xi. 47.) 

 Frustules with finely punctated lateral 

 portions, between which the central zone 

 (having two puncta at each end) appears 

 like a baud. Two or three bars cross 

 lateral and central portions from one 

 lateral margin to the other, and divide 

 them obscurely into compartments. The 

 lateral view has the margins sinuated, 

 from constrictions corresponding with 

 the transverse bands. 



T. Americana (Bailey). — Frustules 

 quadrangular, resembling those of T. 

 musica, but smaller, more minutely punc- 

 tate, with two transverse bars and two 

 costse in each lateral valve. = T'etra- 

 gromma Americana, Bail. Smithsonian 

 Contr. 1853, p. 7. f. 1. As in 2\ musica, 



the costae resemble notes of music, but 

 are confined to the central compartments 

 of the valves. In the lateral view it 

 resembles the preceding species^ but has 

 fewer cross-bars. 



T. Indica (E., Kiitz.). — Frustules 

 subquadrate (catenated ?), compressed, 

 two or four times constricted; lateral 

 valves densely granidate, central portion 

 smooth, with two puncta at each end ; 

 median costae dilated at the end. KSA. 

 p. 119. = Anaidus IndicKs, E. India, 

 frequent. 



T. Javanensis (EM. pi. 34. 8. f. 16). — 

 The figure resembles T. musica ; but the 

 central portion is marked by longitudi- 

 nal lines, which converge at each end. 



Species known to us only hy name. 



T. Asiatica, Asia. = Tetray7'atntna Asi- 

 atica, E. 



T. Japonica (E.), Japan. 



T. Austrahs (E.), Sandwich Islands. 



