Fig. 118. Type figures of C. cancellata, from Brady (1884) ORIGINAL DESIGNATION: Cyclammina cancellata Brady, 1879. TYPE REFERENCE: Brady, H.B. (1879). Notes on some of the reticularian Rhizopoda of the "Challenger" Expedition; Part I. On new or little known Arenaceous types. Quarterly Journal of Microscopical Sciences, 19, p. 62. The type figures are in Brady (1884), pl. 37, figs. 8-15. TYPE SPECIMEN: Deposited in the micropaleontological collections of the British Museum (Natural History). The lectotype specimen, designated by Banner (1966), is the specimen illustrated by Brady (1884) in pl. 37, fig. 9. This specimen is registered as BMNH 1964.12.9.32, from slide ZF 1361 of the Brady Collection. TYPE LEVEL: Recent. TYPE LOCALITY: Not originally designated. Syntype specimens in the Brady Collection are from PORCUPINE stations in the North Atlantic and Mediterranean, CHALLENGER Station 24 off Culebra Island, West Indies, and CHALLENGER Sta. 168. The lectotype is from CHALLENGER Station 168, 1100 fathoms, off the N.E. coast of New Zealand. DIAGNOSTIC FEATURES: Test large, biconvex, planispirally coiled, round to somewhat lobate in outline. Coiling is involute, with 10 to 16 chambers in the last whorl. Megalospheric individuals have an extraordinarily large proloculus (up to 0.75 mm) and are comprised of 2-3 whorls. Microspheric individuals may have 5-6 whorls. Periphery rounded to sub-acute. Sutures are sigmoidal and slightly depressed, curved anteriorly. Apertural face is convex, not alveolar, and contains coarse agglutinated grains. Above the apertural zone of the convex apertural face is a flat, alveolar "super-apertural zone". Primary aperture a basal slit, with supplementary apertures in the apertural face and septae. Supplementary apertures are round and surrounded by lips. Wall is comprised of two layers. The internal hypodermal layer is thick and is perforated by tubular, bifurcating alveoles having constricted openings into the chamber interior. This layer increases in thickness with ontogeny. The outer layer is thin, imperforate, and has a finely finished exterior. SIZE: Lectotype specimen is 3.44 mm in diameter, and paralectotypes are up to 3.16 mm. The specimen illustrated by Brady in Plate 37, fig. 8 from a PORCUPINE station in the North Atlantic is 4.6 mm in diameter. Theyer (1971) reported specimens up to 6 mm in diameter. SYNONYMS: Cyclammina compressa Cushman. Cushman, J.A. 1917, Proc. U.S. Nat. Mus. 51, p. 653 [Recent, Pacific]. Cyclammina pauciloculata Cushman. Cushman, J.A. 1917, Proc. U.S. Nat. Mus. 51, p. 653 [Recent, Pacific]. OBSERVED OCCURRENCES: Brady (1884) recorded this species from 20 stations in the North Atlantic, between 75 and 2675 fathoms, four stations in the South Atlantic, 100 to 1990 fathoms, and 8 stations in the Pacific, 147 to 1400 fathoms. According to his records it is most common between 250 and 1000 fathoms. Saidova (1961) reported it from 40 stations in the northwest Pacific, from 2760 to 7660 m. She noted it was most common between 4500 and 6000 m. Cushman (1920) listed it from 29 ALBATROSS stations in the western North Atlantic and Gulf of Mexico, between 82 and 1345 fathoms. Cushman (1921) recorded it from 16 ALBATROSS stations in the Philippine Seas, from 381 to 1719 m. Cushman noted that its maximum abundance is at depths less than 1000 fathoms. Phleger & Parker (1951) reported it from depths greater than 150 m in the northwestern Gulf of Mexico. Hofker (1976) recorded it from 800 m off St. Croix in the Caribbean. Harloff & Mackensen (1997) reported it as common between 3300 and 4400 m in the Argentine Basin and Scotian Sea. Although common along the continental margins of the Atlantic and Pacific, C. cancellata is rare in the Antarctic seas. South of about 52° in the Drake Passage, it is replaced by C. orbicularis and C. pusilla (Bandy & Echols, 1964; Herb, 1970). KNOWN STRATIGRAPHIC RANGE: Late Eocene to Recent. BATHYMETRY: Bathyal to abyssal. Its modern upper depth limit is reported to be at ~500 m off Chile (Bandy & Rodolfo, 1964) and in the Gulf of Mexico (Pflum & Frerichs, 1976). However, the C. cancellata plexus may be characteristic of shallower facies in the Miocene upwelling areas. The "Cyclammina/Valvulina Biofacies" is observed at the edge of the continental shelf in northeastern Venezuela, where the facies is interpreted as outer neritic to upper bathyal (Moreno-Vasquez, 1995). REMARKS: Cushman (1917, 1920) differentiated the species Cyclammina compressa by its smaller size, more open and depressed umbilicus, evolute coiling, and more acute periphery. The syntypes preserved in the Cushman Collection (CC420) are from ALBATROSS Station 5470, East of Luzon, 540 fathoms. The specimens are over 3 mm in diameter, and have an average of 14 chambers in the final whorl. Banner (1970) regarded this form to be conspecific with C. cancellata based on the structure of the hypodermus and alveoles. Based on sections of numerous Recent specimens of Cyclammina from a 800 m station west of St. Croix, Hofker (1976) concluded that C. compressa is simply a megalosphaeric form of C. cancellata. Specimens consistent with the description of C. compressa were smaller, more compressed, and slightly evolute with a proloculum diameter of 23-32.5 µm, whereas typical specimens of C. cancellata were larger (3-5 mm in diameter), and all microsphaeric with proloculum diameters of 6-15 µm. In the microsphaeric generation, the early chambers are non-alveolar. Fig. 118-2. Variation in the test diameter of C. cancellata with water depth in surface sediments from the Peru-Chile Trench area, from Theyer (1971). Unshaded box represents standard deviation, shaded box is the standard error of the mean. ILLUSTRATIONS: Plate 118a,b - Cyclammina cancellata Brady Plate 118a - Fig. 1a,b. Recent, Paralectotype from the Brady Collection, BM(NH) 1964.12.9.6, CHALLENGER Station no. 168, 1100 fathoms off N.E. New Zealand; Fig. 2a,b. Recent, Paralectotype from the Brady Collection, BM(NH) ZF 4884, ex slide ZF1361, CHALLENGER Station no. 168, 1100 fathoms off N.E. New Zealand; 2b- enlargement of apertural face showing supplementary apertures with well-developed lips; Fig. 3a,b. Recent, Paralectotype from the Brady Collection, BM(NH) Slide ZF 4898, ex slide ZF 1361, CHALLENGER Station no. 168, 1100 fathoms off N.E. New Zealand; Fig. 4a-c. Recent, Paralectotype from the Brady Collection, BM(NH) Slide ZF 4899, ex slide ZF 1360, CHALLENGER Station no. 24, 360 fathoms off Culebra Island, West Indies; 2c- enlargement showing sponge spicules incorporated into apertural face. Plate 118b - Fig. 1 Successive chambers of a megalospheric specimen showing the development of the hypodermis during ontogeny; Fig. 2. Axial section of megalospheric specimen showing hypodermal alveoles in cross section and extent of the aperture; Fig. 3. Megalospheric specimen showing eroded apertural face; Fig. 4. Apertural view of another megalospheric specimen; Fig. 5. Microspheric specimen with eroded apertural face; Fig. 6. Equatorial section of a microspheric specimen, BM(NH) Slide 1964.12.9.2. All specimens from CHALLENGER Station no. 168 |