794 



SYSTEMATIC HISTOEY OF THE INFUSOEIA. 



folds. = Surirella Ovum, Nageli in KSA. 

 p. 889. Switzerland. 1-360" to 1-280". 



The characters given are insufficient to 

 distinguish it from C. elliptica. 



Genus SURIRELLA (Turp., E., S.). — Erustules simple, free; margin 

 striated ; lateral smfaces broader than the front view, with a smooth median 

 lon^tudinal line ; " margins produced into aloe, canalicuH distinct, usually 

 parallel" (Smith). SuiireUa thus Hmited by Professor Smith becomes a much 

 more natm^al genus than it was constituted by preceding authors : he says, 

 *' It is weU distinguished from TryblioneUa by the prominency of its alae, the 

 distinctness of its canaUcuH, and the usually cuneate form of its frustules ; 

 mth no other is it at aU likely to be confounded." 



few, reaching the median line, central 



* Frustules panduriform. 



SuRiEELLA constricta (E.). — Large, 

 oblong, in lateral view panduriform, with 

 a median line and iutramarginal crena- 

 tions. EM. pi. 14. f. 37. Benticula con- 

 stricta, KB. t. 3. f. 62 ?. Aquatic. Berlin, 

 (xiii. 3.) Ehrenberg's figure in the ^Mi- 

 crogeologie' seems a true species of this 

 genus; and different as is that oiDenticula 

 constricta in Kiitzing's work, yet, as it was 

 copied from a figure given by Ehrenberg 

 in an earlier work, the differences are pro- 

 bably due to the imperfect representation. 



S.' Smithii (K.). — Front ^dew broadly 

 linear, with truncate ends and rounded 

 angles; lateral view panduriform, with 

 attenuated ends ; costge delicate, reach- 

 ing the median line, which is often in- 

 flated. = ^. constricta, SBD. i. p. 31, pi. 8. 

 f. 59. Brackish water. England. Alae 

 conspicuous, enclosing an oblong space. 

 1-300". The shape, in front view, re- 

 sembles that of S. hiseriata, but the costse 

 are much finer. 



S. Antarctica, EM. pi. 35 a. 2. f. 20. 

 Antarctic Sea. "We have seen no de- 

 scription of this species. Ehrenberg's 

 figure shows the lateral view panduri- 

 form, vdth rounded ends and strongly 

 marked striae, which nearly reach the 

 median line. 



S. didijma (K.). — Oblong, with trun- 

 cate ends, constricted middle and punc- 

 tated margins. KB. p. 60, t. 3. f. 67. 

 Submarine waters. Isle of Wangeroog. 

 1-600". This appears to us a doubtful 

 species of Surirella ; for Kiitzing's figure 

 seems to represent a frustide constricted 

 in the front view, as it shows a linear 

 median portion truncated at its ends. 



S. panduriformis (Rab.). — Resembles 

 S. didyma, but is stouter, and its mar- 

 ginal dots appear stalked. Rab. p. 29, 

 t. 3. f. 9. Italy. 



2 * Lateral vieic lanceolate or oblong, with 

 its ends usually equally cdtenuated. 



S. Craticula (E.). — Lanceolate; costas 



ones divergent. SBD. pi. 9. f. 67. Aquatic. 

 Australia, Asia, Africa, America, Britain. 

 (XII. 19, 20.) Costfe 7 in 1-1200". 

 1-288". The central costse are usually 

 more distant, leaving a transverse smooth 

 space bisected by the median line. 

 Smaller than S. hiseriata ; its costce fewer 

 and more divergent. 



S. megaloptera, EM. pi. 33. 1. f. 17. 

 Eg}^t. The figure resembles that of 

 *S', Craticula ; but the costse are all paral- 

 lel, and the median line, as well as costse, 

 are interrupted at the centre by a broad, 

 transverse band. 



S. hiseriata (Breb.). — Front view qua- 

 drilateral, with conspicuous alse ; lateral 

 view oblong-lanceolate, with broad costse, 

 which usuallv reach the median line. 

 SBD. i. p. 30, "pi. 8. f. 57. = .^. hifrom, E. 

 Common. (x\t:. 20-26.) Differs from 

 S. splendida Iby its parallel sides in front 

 \4ew. Its angles are rounded, and the alse 

 enclose an oblong space; its costse are 

 conspicuous in both views. 1-210" to 

 1-100". Sti-i^ 3L in 1-1200". 



S. decora (E.). — Large, linear-lanceo- 

 late, with equal, attenuated ends and 

 four or five marginal costse in 1-200". 

 EM. pi. 5. 3. f. 23. America, Ireland. 

 Ehrenberg's figures are oblong lanceo- 

 late, one of them constricted. 



S. rejlexa (E.). — Lanceolate, with 

 nearly equal, slightly refiexed, subacute 

 ends, a distinct median suture, and strong, 

 short strise, in the middle three or foiur 

 in 1-1152". EM. pi. 33. 11. f. 13. Fossil. 

 Connecticut. 



S. leptoptera (E.). — Lanceolate, with 

 nearly equal, acute ends, a distinct, di- 

 lated median suture, and dense trans- 

 verse strise, which in the middle are 

 6 in 1-1152". KSA. p. 36. Fossil. 

 Oregon. A specimen 1-456" long pre- 

 sented 21 strise. 



S. Oreyonica (E.). — Spathulate, with 

 imequal, subacute ends, a distinct, di- 

 lated median suture, and strong strise, 

 which in the middle are four or five in 



