Algse, Bacillariese, Cryptorhaijhidese, CoscinodiscaceEe, Coscinodiscus. 29 



5. Coscinodiscus atlanticus Castrac, Diat. Chall., p. 158, t. V, f. 8. 92 

 Rattr., 1. c, p. 30. Castrac, Trip. mar. valle Metaur., p. 5. — 

 Disco 45-46 a. diam. metiente, spatio centrali rosulaque nullis, 

 granulis rotundatis, sine ordine dispositis (interstitiis hyalinis e 

 centro paullo ultra semiradium conspicuis) dein polygonis, subaequa- 

 libus, 10 in 10 a. prope marginem in series subfasciculatas radian- 

 tes dispositis; margine distincto, hyalino. 



In tripoli loci dicti u Tombolina » vallis Metaurensis in agro 

 Umbro (Castrac ). 



6. Cosclnodiscus Kuetzlngli A. Schm., Atlas, t. LVII, f. 17, 18. Rattr., 93 

 1 c, p. 33. Castr., I. c Coscinoclzscus marginatus A. Schra., Nords. 

 Diat., 1874, p. 94, t. III, f. 35. — Disco 63-64 u.. diam. metiente; 

 spatio centrali absente ; areolis polygoniis, circiter 6 in 10 y.., sub- 

 lequalibus vel marginem versus leniter decrescentibus, seriebus ultra 

 semiradium distincte fasciculatis (seriebus secundariis oblique de- 

 cussatis evidentibus marginemque versus incurvis); margine acute 

 definito series confertas oblique decussatas areolarum praebente. 



Cum praecedenti (Castr.). 



7. Coscinodiscus curvatulus Grun., in A. Schm.. Atlas, LVII, f. 33. 94 

 Rattr., I. c, p. 38. Castrac, 1. c Coscinodiscus curvatulus var. 

 inermis Grun., Diat. Fr. Jos. Land, 1884, p. 83, t. 4, f. 11-12 ;A. 

 Schra., Atlas Diat., t. 113, f. 6. Odontodiscus curvaiulus Cleve, 

 Diat. of Vega Exped., 1885, p. 488. — Disco 45-70 y.. diam. metiente, 

 spatio centrali absente vel imperspicuo, granulis numerosis rotun- 

 datis instructo; areolis (in cetera superficie valvae) polygoniis, sub- 

 aequalibus, 6 in 10 a., seriebus eleganter incurvis, fasciculatis, curva 

 serierum in altera valva opposite disposita; seriebus secundariis 

 oblique decussatis obviis; apiculis nullis. 



In depositu a Caltanisetta » insulse Sicilice (Rattray), in tripoli 

 vallis Metaurensis loci dicti «Tombolina» in agro Umbro (Ca- 

 strac). — Var. mlnor Grun., Diat. Franz Josephs-land, p. 83, 

 t. IV, f, 8-10. Rattr., 1. c, p. 39. Coscinodiscus minor A. Schm., 

 Atlas Diat , t. 58, f. 40. — Disco 30-40 a. diara. metiente; spatio 

 centrali parvo et granulari, aut absente, seriebus rectis, niinus di- 

 stincte fasciculatis, secundariis obliquis inconspicuis, apiculis nullis. 



Fossilis in depositis u Caltanisetta et Girgenti » insuhe Sicilice 

 (Grunow, Nicotra). 



8. Cosclnodiscus stellaris Roper., in Quart. Journ. Micr. Sc, 1858, 95 

 p. 21, t. III, f. 3. Rattr. 1. c, p. 45. Castrac, Trip. raar. valle 

 Met., p. 5; Diat. of Challenger Exped., 1886, p. 155, t. 3, f. 2, p. 158, 



