~V~ ~\|ol . = a aad =78 n = I ee a ee ‘ B-4 Zaaees eg ee Se a ae 2. a>: a SOL Ne eet enn a a oe ee ee . ee ee et Se lk 6 ? @TEESOg TOEO g NLELAG nig Ta PT Pre - ALLAN HANCOCK FOUNDATION PUBLICATIONS LL L+H OF pe P a y 4 —f THE UNIVERSITY OF SOUTHERN CALIFORNIA FIRST SERIES ALLAN HANCOCK PACIFIC EXPEDITIONS VoLuME 14 1950 - 1953 THE UNIVERSITY OF SOUTHERN CALIFORNIA PRESS LOS ANGELES, CALIFORNIA 1953 ALLAN HANCOCK FOUNDATION PUBLICATIONS ALLAN HANCOCK PACIFIC EXPEDITIONS VoLuUME 14 1950 - 1953 THE UNIVERSITY OF SOUTHERN CALIFORNIA PRESS LOS ANGELES, CALIFORNIA 1953 CONTENTS PAGES ie helostomata~Anasca (Plates 1-29) 2 1-191 Ree SET OTICES 22 ck yc ee eee ees ae eee eae 192-197 BR ip es! a 6 Val nS es a ee hee ee ee ee 199-257 Mira heer 2s 2 a NE ee Re ee ee 259-269 2. Cheilostomata-Ascophora (Plates 30-64) -....................-----.-- 271-518 BCE CIC a a BE Se ee eee 519-525 |) Poe Sie SR tae Me oes tet Ree EAL FEI es) SE 2 528-597 ra ces IE a «ee ee ec eee 599-611 2. JU CETECS oC rr a ca beatae tte Tern SCR a! ae CoE 613-719 Reierences 3) a Loss ne i ee 720-725 VERE LES ET D6! 5 Laie Ra oe RENAN en 726-755 Berenice ie ot ee oat es on 0S 756-758 Pas TOCE A. ee eC aes SAC el ends) I) cs oe 759-771 Ieererences ster es 2 08 a 772-773 21s LST UNIS nt ee ve BS EL NP Co 2 774-782 re teremcess ee ee ie ts es a ee 783-784 SELES ote LAAN SRE ek RO a re Cae EC 787-823 erred che ee ay a ee SS 827-834 Index for Orders, Divisions, Families, Genera, and Species..... 835-841 5H? RAS REPORTS ON THE COLLECTIONS OBTAINED BY ALLAN HANCOCK PACIFIC EXPEDITIONS OF VELERO III OFF THE COAST OF MEXICO, CENTRAL AMERICA, SOUTH AMERICA, AND GALAPAGOS ISLANDS IN 1932, IN 1933, IN 1934, IN 1935, IN 1936, IN 1937, IN 1938, IN 1939, IN 1940, AND IN 1941, AND VELERO IV IN 1949, BRYOZOA OF THE PACIFIC COAST OF AMERICA PART 1, CHEILOSTOMATA-ANASCA (Piates 1-29) By RAYMOND C. OSBURN, Pu.D., D. Sc. THE UNIVERSITY OF SOUTHERN CALIFORNIA PUBLICATIONS ALLAN HANCOCK PACIFIC EXPEDITIONS VOLUME 14, NUMBER 1 IssuED JUNE 20, 1950 Price $5.00 THE UNIVERSITY OF SOUTHERN CALIFORNIA PRESS Los ANGELES, CALIFORNIA BRYOZOA OF THE PACIFIC COAST OF AMERICA Part 1, CHEILOSTOMATA—ANASCA By Raymonp C. Ospurn, PH.D., D.Sc. A report based chiefly on the Bryozoa collected by the Allan Han- cock Expeditions, 1933-1942, in the Velero III. The ten cruises of the Velero III and shore collections extended from the coast of Oregon to San Juan Bay, Peru, and included the oceanic islands off the coast, Socorro, Clarion, Cocos and the Galapagos. Five visits were made to the Galapagos area, otherwise the most intensive collecting was done about the islands off southern California, southward along the coast of Lower California and in the Gulf of California, a total of more than 1500 dredge-stations and 2000 additional bottom samples. Various other institutions have contributed Pacific coast specimens toward the completion of this work, usually local material. The United States National Museum has loaned the Bryozoa from a number of the “Albatross” stations and from the Alaska Crab Investigation. The American Museum of Natural History contributed a small amount of material from the ‘‘Albatross” expedition of 1911 along the coast of Lower California. The California Academy of Science gave free access to the Bryozoa collection, made chiefly by Dr. Alice Robertson. The Hopkins Marine Station at Pacific Grove, California, presented me with a large collection, mostly from that area, made by Miss Elizabeth A. Blagg. The Pacific Biological Station at Nanaimo, British Columbia; the Oceanographic Laboratory at Friday Harbor, Washington; the Pacific Marine Station at Dillon Beach, California; the Kerckhoff Ma- rine Station at Corona del Mar, California; the Scripps Oceanographic Institution at La Jolla, California, and the Los Angeles County Museum have all aided by the contribution of specimens. Also Dr. Paul L. Galt- soft of the U. S. Fisheries and Wildlife Service has permitted me to study the Bryozoa on a collection of pearl oyster shells (Margaritiphora mazat- lanica) from the Gulf of Panama, about 60 species. A large gap in our knowledge of the high northern species of the Pacific coast has been well filled by the contribution of 80 species from Point Barrow, Alaska, by Read 2 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Professor and Mrs. G. E. MacGinitie of the Alaska Research Labora- tory. To all of these the author is grateful for the opportunity to further our knowledge of the distribution of the Bryozoa of the Eastern Pacific area. HIsToRY The Bryozoa of the Pacific coast of the Americas have received but little attention in the past, except in a few limited areas. The first record of species is that of Alcide d’Orbigny (Voyage l’Amérique Méridionale, 1841-7), who listed 14 species from the west coast of South America as far north as the coast of Peru but, unfortunately, due to incomplete descriptions and figures, some of his species cannot be determined posi- tively. In 1856 Busk described and listed 15 species from Mazatlan, Mexico, and in 1857 Trask recorded 5 species from the vicinity of San Francisco. Fewkes in 1889 described Clavopora (Ascorhiza) occidentalis from southern California. A few other scattering records appear in the works of Busk, Hincks, Waters, etc. In the years 1882-4 the first important study of Pacific Bryozoa ap- peared in Hincks’ report on “‘Polyzoa of the Queen Charlotte Islands,” the material having been collected by Dr. G. W. Dawson of the Canadian Geological Survey. In this report Hincks recorded about 95 species and varieties from the waters of British Columbia, many of them new. Dr. Alice Robertson’s important work began in 1899 with a short paper on the Entoprocta of San Francisco Bay, and this was followed in 1900 by a list of 36 species taken by the Harriman Alaska Expedition, but her greatest contribution was the series of three papers (1905, 1908 and 1910) on Bryozoa of the West Coast of North America. The area covered was practically that of the west coast of the United States from Puget Sound, Washington, to San Diego, California, though some more northern forms were discussed, a total of 98 species. Dr. Chas. H. and Elsie O’Donoghue in 1923, “A preliminary list of Bryozoa from the Vancouver Island Region,” listed 170 species and 22 varieties. This was followed in 1926 by a ‘“‘Second List,” in which the nomenclature was revised and 20 species added. In 1930 there appeared two papers dealing with limited tropical areas. The first of these, ‘““The Bryozoan Fauna of the Galapagos Islands,” by Canu and Bassler, recorded 56 species, many of them new, from three dredge hauls made by the U. S. Str. “‘Albatross.”” The second, by Dr. Anna B. Hastings, ““(Cheilostomatous Polyzoa from the vicinity of Pana- No. | OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 3 ma Canal collected by Dr. C. Crossland on the cruise of the S. Y. St. George,” listed 62 species, 27 from the Gulf of Panama, 33 from Gor- gona, Colombia, and 37 from the Galapagos Islands. It appears that the only region of the Pacific coast that has been at all adequately covered is the area from Puget Sound to southern Alaska. Robertson apparently had very little dredged material at her disposal and the number of species along the coast of the United States recorded by her is limited almost entirely to shallow water forms. Of the several thousand miles of coast from southern California southward we have had no information except for the small areas covered by the papers of Hast- ings and Canu and Bassler. Similarly we have had only very limited knowledge of the bryozoan fauna from southern Alaska northward. The very extensive material dealt with in the present report should give a fair picture of the occurrence of the coastwise Bryozoa of the Eastern Pacific area from northern Alaska to Peru. No doubt many species will be added in the future and certainly our knowledge of the distribution will be greatly increased. DIsTRIBUTION As might be expected, no sharp distributional barriers have been found; instead there are several areas which are more or less distinct in their faunas but which intergrade with the regions to the north and south. Still, when one considers a sufficient number of species from any one of the following regions, the bryozoan facies is distinct enough ex- cept where the boundaries overlap. here are some species which appear to disregard temperature and range from the arctic to the tropics. 1. The arctic area of the Pacific coast extends from Point Barrow, Alaska (71° 18’ N Lat.), the most northwesterly part of the North American coast, southward to the Alaska Peninsula and the Aleutian Islands. In the Bering Sea only a few scattering collections have been made, but all of the species are high northern or arctic forms. Our know]- edge of this area has been recently much extended by the work of Profes- sor and Mrs. G. E. MacGinitie of the Arctic Research Laboratory at Point Barrow. In the summer of 1948 they collected more than 80 bryozoan species, practically all of which are known to occur elsewhere in the North Polar seas. Several of these species extend their range southward to British Columbia and even to northern California. 2. Acool water region extends from the Alaska Peninsula southward to Point Conception, California (about 35° N Lat.). The northern part of this range is rather distinct from the southern portion, but so + ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 many species are found through the whole area that no line of separation can be drawn. The more northern species tend to disappear south of Vancouver Island and the more southern ones at the same point, but Puget Sound and southern British Columbia show a great mixture, with even a few warm water species present. In spite of the latitude, there is cool water along the California coast, with occasional inlets where the temperature is somewhat higher. 3. A more temperate area extends from Point Conception and the northern Channel Islands off southern California to Cedros Island and Point Eugenia, half way down the peninsula of Lower California (27° 30’ N Lat.). In addition to numerous species characteristic of moderate temperature there is a great mixture, with some of the more northern species reaching their limit among the Channel Islands and an increasing number of tropical species south of the Mexican boundary. 4. The truly tropical area extends from Cedros Island and the same latitude (27° 30’) in the Gulf of California to the vicinity of San Juan Bay, Peru (15° 20’ S Lat.). Throughout this wide area there is much similarity in the bryozoan fauna and the great majority of the species are limited to tropical waters. Moreover, most of the species are found widely distributed along this coast and about the outlying islands (Socorro, Clarion and the Galapagos). No doubt there are endemic species which are limited to a narrow range, but it would be hazardous to predict this in any case, as continued dredging may recover them in unexpected areas. Species hitherto known only from the Galapagos Islands have been taken by the Allan Hancock Expeditions at various places along the mainland, even as far north as the coast of Mexico and the Gulf of California. ACKNOWLEDGMENTS To Captain Allan Hancock, Director of the Allan Hancock Founda- tion, who through financial assistance has made possible this extended research, I owe a deep debt of gratitude. To Dr. Irene McCulloch of the Foundation, who has placed many facilities for work at my disposal and whose interest in the progress of the work has been an inspiration, I am also deeply thankful. Dr. Arthur D. Howard, Mr. John D. Soule, and Miss Mary G. Marsh have relieved me of much tedious sorting of ma- terial. I must here also record the valuable assistance of my friends, Dr. R. S. Bassler of the U.S. National Museum and Dr. Anna B. Hastings of the British Museum of Natural History; Dr. Bassler has given me access to valuable type material, Dr. Hastings has made numerous com- parisons for me, and both have presented me with specimens important for this study. No. | OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 5 GLOSSARY Many of the following list of terms have a special application in the Bryozoa and the beginner in this group may find the definitions useful. Ancestrula. The primary individual of a colony, derived by metamor- phosis from the free-swimming larva. Aperture. The orifice through which the tentacles are protruded, usu- ally closed by an operculum in the Cheilostomata. Avicularium. A modified and usually much reduced individual of a colony, without a polypide and bearing a mandible. They may be vicari- ous (interzooecial) or dependent (borne on some part of a zooecium). Cardelles. Lateral denticles in the aperture for the attachment of the operculum, often wanting in the Anasca. Communication pore. See Septulae and Dietellae. Costules. Radiating ridges forming the frontal pericyst in the Cribri- morpha, they are modified marginal spines. Cribrimorphs. Zooecia with a costulate front (Cribrilinidae, etc.). Cryptocyst. A calcified inward extension from the mural rim in the Anasca, often vestigial. Between it and the ectocyst is a space, the hypo- stege, which serves as a hydrostatic chamber when the tentacles are ex- tended and withdrawn. Cell. Old name for a zooecium. Dieiellae. Small cavities around the base of the zooecial wall, in which the communication pores are located. Distal. In Bryozoa, directed toward the oral end of the zooecium. Dorsal. The side of the zooecium opposite that on which the aperture is located. Ectocyst. The chitinous membrane which covers the zooecium. Endocyst. The thin membrane lining the zooecium and enclosing the body organs. Endozooecial. Referring to a type of ooecium (ovicell) formed by the forward extension of the distal zooecial wall. (Compare with Hyper- stomial. ) Front, frontal. The side of the zooecium on which the aperture is located. Gymnocyst. The calcified area of the covering membrane in Anasca. It is usually limited to the proximal end and is often vestigial or wanting. Gonozooecium. A modified zooecium specialized for reproduction. Heterozooecium. An avicularium or vibraculum, a highly modified and usually much reduced individual of the colony, without polypide but 6 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 with powerful muscles to operate the mandible. They are sometimes vestigial. Hyperstomial. Referring to external ovicells. These are often more or less embedded in the gymnocyst of the succeeding zooecium but careful dissection will show that they arise above the distal wall of the zooecium to which they belong. Hypostege. A cavity between the ectocyst (frontal membrane) and the cryptocyst in the Anasca, the hydrostatic chamber. Kenozooecium. A member of the colony in which there is no polypide and usually no aperture, such as the stalk segments of Caulibugula, the internodes of radicles, etc. Lacunae. Pores between the costae of the cribrimorphs. Lumen. A clear line or pore on the middle of a costule in the cribri- morphs. Lucida. A clear area in a chitinized membrane such as the operculum or mandible. Mandible. ‘The chitinous movable part of an avicularium; it is ho- mologous with the operculum of a zooecium. Mural rim. The frontal edge of the side walls, often bearing spines in the Anasca. Onychocellarium. An avicularium in which the mandible has lateral membranous expansions (winged). Ooecium. Any structure containing the larva during its development ; it may be either hyperstomial or endozooecial. Operculum. A chitinous membrane which closes the aperture like a trap-door in the Cheilostomata. In the Anasca it is connected proximally with the frontal membrane. Opesia. The large orifice beneath the frontal membrane of Anasca; often occupying nearly all of the frontal area. Opesiule. A small perforation or notch in the cryptocyst for the pas- sage of muscles to the ectocyst in Coilostega (e.g. Thalamoporella). Ovicell. ‘The same as Ooecium. Pedunculate. Elevated on a stalk or pedicel, referring usually to avicularia. Pericyst. A calcified frontal above the ectocyst in certain Anasca, usu- ally formed by the fusion of marginal spines. Peristome. An elevated rim around the aperture. Polypide. That part of the individual freely movable within the body wall and including the tentacles and intestinal tract. Pore chamber. See Dietellae. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 7 Proximal. Directed toward the point of origin of the zooecium. Radicle. A root-like structure in certain Anasca, serving for attach- ment, usually consisting of a series of kenozooecia. Sclerite. Amarginal or other thickening of the operculum or mandible. Septulae. Very small communication pores in the zooecial walls; they are either scattered singly, or aggregated in groups (uniporous or multi- porous rosette plates). Spicule. A small spine without an internal canal. Spine. A hollow projection, more or less elongate, either open or closed at the tip, marginal or oral. Stolon. A creeping stem, consisting of kenozooecia, from which zooecia may arise. Tentacles. Long ciliated projections around the mouth, serving to di- rect the food. Umbo. A prominence on the frontal area usually a short distance proximal to the aperture (in the Anasca usually limited to the Cribri- morpha). Unguiculate. Shaped like a claw or talon. Vibraculum. A highly modified avicularium, in which the long lash- like mandible can be moved in various directions. Vicarious. Referring to avicularia occupying a place in the zooecial series (interzooecial ). BRYOZOA Ehrenberg 1831 This is a very distinct phylum of the Invertebrata, separated by a number of important characters. The name was suggested by the erect, moss-like appearance of the colonies of some of the species, but as a mat- ter of fact, most of the species are encrusting and more like lichens than mosses in their manner of growth. The term “Polyzoa,” which is still in use by English authors, was applied in 1830 by J. V. Thompson and thus antedates Ehrenberg’s name for the group, but has been generally discarded on the ground that Thompson did not use this term as a class name. Cori (1929) separated the Entoprocta from the Bryozoa to form a distinct phylum Kamptozoa. Whether this arrangement will finally be accepted or not need not concern us here, as the bryozoologists will no doubt continue to include them in their studies. With a few exceptions among the Entoprocta, the Bryozoa are highly colonial, budding in various ways (terminal, lateral, dorsal, frontal, stolonate) to produce colonies which frequently consist of many thousands 8 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 of individuals. The individuals (usually less than a millimeter in length) are provided with a calcified or chitinous outer wall (zooecium) into which the lophophore and tentacles are retractile (in the Entoprocta the polypide is naked and the tentacles are simply rolled inward). The great majority of the species are marine, distributed from the polar regions to the tropics and from the shore line down to great depths. They are abun- dant as fossils from the Ordovician to Recent time. CLASSES OF THE BRYOZOA Polypide naked, stalked ; tentacles rolled inward, not withdrawn into the zooecium; anal opening within the tentacle ring. _ ENTOPROCTA Belepiie ERG ina eee or era wall (Geoteee tenta- cles retractile; anal opening outside of the tentacle ring. . ECTOPROCTA ORDERS OF THE ECTOPROCTA Mostly marine, with a circular tentacle ring. . GYMNOLAEMATA Fresh-water Ectoprocta, with a horse-shoe shaped tentacle ring. PHYLACTOLAEMATA SUBORDERS OF THE GYMNOLAEMATA 1. Zooecium chitinous, its opening usually circular, closed by a puck- ering membrane .. . ~ +.» « CERENOSTOMAE. 2. Zooecium calcified, its opening ies not closed by an operculum. : : ‘ ; CYCLOSTOMATA a: Zaeecial mile deuall well ieee opening by a movable opercu- lar valve like a little trap-door. . . . CHEILOSTOMATA Suborder CHEILOSTOMATA Busk, 1852 The cheilostomes form the dominant group among the recent Bryozoa. The zooecia are chitinized and usually calcified, often heavily so. In all but a few cases there is a chitinized operculum which operates like a trap-door to open and close the aperture through which the tentacles are extruded and withdrawn. Hydrostatic apparatus. As the walls are rigid, compensation is neces- sary for the changes in internal pressure when the tentacles are protruded or withdrawn and this is accomplished by two methods: 1. there is a membranous area on the front of the zooecium which rises and falls with the changes in pressure (Anasca) ; 2. when the front is solidly bridged over (Ascophora), there is an internal water sac (compensation sac or compensatrix ) which fills and empties through a special pore. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 9 Communication pores. For physiological communication between ad- jacent individuals there are minute pores in the lateral and distal walls. These are of three kinds: 1. uniporous septulae which are arranged in a row or scattered; 2. multiporous septulae, in which case the pores are aggregated in small rounded areas known as “rosette plates ;’’ 3. dietellae or “pore chambers,” which are in the form of small cavities at the base of the vertical walls and within which the pores are located. Polymorphism. This a common feature of this group and various names have been given to the different types of individuals: 1. autozooecia to the ordinary nutritive members of the colony; 2. gonozooecia to those specially modified for reproduction; 3. heterozooecia and kenozooecia to those modified for other functions of the colony (see glossary). Ovicells. Ooecia or ovicells are usually present, though in some cases the eggs develop to the swimming larval stage within the zooecial cavity. Endozooecial ovicells are internal extensions of the distal wall to form small chambers, with the opening below the operculum; usually they are inconspicuous, but may be quite evident externally. Hyperstomial ovi- cells are developed above and distal to the aperture, usually reposing on the base of the next zooecium, and the orifice opens above the distal zooecial wall. Avicularia and vibracula. These are highly modified and usually much reduced individuals of special function, serving as zooecial or colonial organs (see glossary). Levinsen (1909) subdivided the Cheilostomata into the Anasca, which have a membranous frontal area and no compensatrix, and the Ascophora which have a rigid frontal area and in which the compensatrix regulates the internal water pressure. ANASCA Levinsen, 1909 Levinsen (1909:91) defined the “Suborder Anasca” as follows: “A compensation sac is wanting, and the front wall is either wholly or in part membranaceous, or calcareous, depressed and surrounded by raised margins. In the heterozooecia the opercular and the subopercular areas are as a rule not separated by a continuous calcareous bar, but only partially by the hinge-teeth of the operculum.” At the same time he set up three divisions: Malacostega, Coilostega and Pseudostega. The Malacostega, Division I, was defined, “The individual zooecia are plainly marked off on the surface of the colony. The frontal wall quite or partially uncalcified and the operculum as a rule a membranous valve, the rim of which is chitinized, but which proximally passes over 10 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 into the frontal membrane.” He included in the Division the families Aeteidae, Bicellariidae, Farciminariidae, Scrupocellariidae, Flustridae, Membraniporidae, and Cribrilinidae. It is quite evident that Levinsen included too wide a range of anascan forms within the division and Har- mer later (1926) removed all but Levinsen’s ‘““Membraniporidae” and “Flustridae”’ to other divisions and arranged them in the following manner: Division I. Inovicellata Jullien, 1888, Family Aeteidae. II. Malacostega Levinsen, 1909, Membraniporidae, Flustri- dae and their allies. ILI. Coilostega Levinsen, 1909, the Opesulidae of Jullien and related families. IV. Pseudostega Levinsen, 1909, Cellariidae. V. Cellularina Smitt, 1867, Scrupocellariidae, Bicellariel- lidae and related forms. VI. Cribrimorpha Harmer, 1926, Cribrilinidae. This arrangement has generally been accepted by later authors. Still more recently Silen (1942:56), has set up another arrangement of the anascan groups, and introduced two new “‘sections.” It is quite possible that his system may be nearer the truth, but as all of the species dealt with in this report fall within the scope of Harmer’s system, that arrangement will be followed. Division I INOVICELLATA Jullien, 1888 The zoarium is creeping, adnate and stolon-like. At intervals there are swollen, spindle-shaped enlargements, from each of which rises an erect zooecial tube with an operculum like a minute trap-door at the upper end. The zooecium consists of both the erect tube and the basal enlargement, as the polypide extends into both of them. There are no avicularia, vibracula, spines, nor permanent ovicells, though temporary membranous ovicells may be present until the eggs have undergone at least a part of the larval development. Polypide regeneration may occur, in which case a new “head” with a new operculum extends beyond the primary zooecial tube. One family and one genus in this Division. No.1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 1 Family Aeteidae Smitt, 1867 Genus Aetea Lamouroux, 1812 Genotype, Sertularia anguina Linnaeus, 1758 :816 Key TO THE SPECIES 1. Zooecial tube coarsely wrinkled or corrugate. . . . . . Jligulata Zooecial tube very finely or not all annulate. , . . .... 2 2. Erect tube entirely without annulations. . . . . . . truncata Very fine annulations present . . . reer A AS) 3. Terminal expansion spoon-shaped, base not CEES . . anguina Terminal expansion narrower, basal expansion also finely SIUTUINE ALES Sesh ical Ae ree a a Oe ree, EN va ELE Aetea anguina (Linnaeus), 1758 Plate 1, fig. 3 Sertularia anguina Linnaeus, 1758 :816. Aetea anguina, Robertson, 1905 :244. Aetea anguina, O’ Donoghue, 1926 :39. Aetea anguina, Hastings, 1930:702. This little creeping species is practically cosmopolitan and has been listed in nearly every paper dealing with shorewise Bryozoa in the tem- perate and tropical regions. The stolonate portion adheres to stems of hydroids, algae, other bryo- zoans and occasionally to shells and pebbles. The erect tube is often bent or curved snake-like and the expanded terminal portion has somewhat the shape of a snake’s head, so that Ellis in 1755 named it the “snake coral- line.” The “head,” stalk and basal portion all appear to be very finely punctate and the stalk finely annulated. It must be noted, however, that there are no punctations but instead there are minute tubercles which, under transmitted light, appear to be punctures. A flat membranous area occupies one side of the “head” and at the distal end of this area is the operculum which is also thickly “punctate.” The ovicell is rarely ob- served, and apparently it is quite evanescent. I have found it on a few occasions with the embryo surrounded by a very delicate membrane which evidently disappears after the discharge of the ciliated larva. ~ Robertson noted its presence at San Pedro and San Diego, Cali- fornia; O’Donoghue recorded it from Puget Sound, and Gabriola Pass, British Columbia, and Hastings listed it from the Galapagos Islands. On the east coast of the Americas it is a common species from Maine (Osburn 1933:18) to Brazil (Marcus 1937: 26). Cosmopolitan. 12 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 In the Hancock Expeditions it was found at numerous stations from Oregon to Peru and the Galapagos Islands, from the shore line down to about 30 fathoms. Aetea recta Hincks, 1861 Plate 1, fig. 2 ?Hippothoa sica, Couch, 1841:102. (Unidentifiable. ) Aetea recta, Hincks, 1880:6. Aetea sica, Osburn, 1914:186; 1927 :124. Aetea sica, Marcus, 1937: 28. Aetea recta, Osburn, 1940 :346. Resembling 4. anguina in appearance, but the “‘head”’ is narrower and the whole erect portion is straighter. Ihe operculum is set more trans- versely across the end of the tube and the basal portion is annulated with the fine ‘‘punctations”’ like the stalk. Couch may have had this species, but as Hincks points out (1880:7, footnote), the description was drawn from an imperfect specimen, which is entirely unidentifiable and Couch placed the species in the genus Hippothoa. A. recta occurs on the coast of Europe from Norway southward and on the eastern American coast it has been reported from the Tortugas Is- lands, Florida and the Caribbean Sea (Osburn), and from the Bay of Santos, Brazil (Marcus). It seems not to have been noted on the Pacific side of the Americas. Hancock Stations: 325-35; 333-35; 545-36; 1012-39; 1271-41; 1281-41 and 1295-41, from the islands off southern California, the Gulf of California and Galapagos Islands, from the shore down to 80 fathoms. Also from the San Juan Islands, Puget Sound, Dr. J. L. Mohr, collector. Aetea truncata (Landsborough), 1852 Plate 1, fig. 1 Anguinaria truncata Landsborough, 1852 :288. Aetea truncata, Robertson, 1905: 246. Aetea truncata, O’ Donoghue, 1923 :16; 1926 :40. Aetea truncata, Hastings, 1930:702. Aetea truncata, Osburn, 1947:8. The erect tubules are straight, truncate at the tip and vary widely in height. Both the erect and basal portions are very delicately ‘“‘punctate,” but lack entirely the minute annulations of anguina and recta. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 13 It is a very widely distributed species, known from the coasts of Europe, the Indian Ocean, the western Pacific from Japan to Australia, the western Atlantic from Nova Scotia to Brazil, and on the American Pacific from British Columbia to the Galapagos Islands. Hancock Stations: dredged at 66-33, Albemarle Island, Galapagos; 391-35, Lobes de Afuera Islands, Peru; off Octavia Rocks, Colombia; 998-39, 1155-40 and 1407-41, Santa Catalina Island, and 1271-41, Anacapa Island, southern California, 10 to 36 fms. Common along shore. Aetea ligulata Busk, 1852 Plate 1, fig. 4 Aetea ligulata, Hincks, 1884:2. Aetea fuegensis Jullien, 1888: 1.25. Aetea crosslandi Waters, 1910: 253. Aetea ligulata, Marcus, 1937 :30. Aetea sica, Canu and Bassler, 1928 :51. Aetea ligulata, Osburn, 1940 :347. The erect portion of the zooecium is straight and the “head” but little wider than the stalk. The stalk is coarsely wrinkled or corrugated, quite different in appearance from the fine annulations of anguina and recta in which the appearance of annulation is produced by the arrange- ment of minute tubercles (“punctations”); the basal portion is also sometimes wrinkled, and both basal and erect portions are also finely “punctate.” Silen (1941:12) has described another species (4. boninensis) from the Bonin Islands, which has a similarly corrugated stalk, but the head is widely expanded and the basal portion smooth. A widely distributed species recorded from Patagonia and the Straits of Magellan (Busk), Queen Charlotte Islands, British Columbia (Hincks), Terra del Fuego (Jullien), Red Sea (Waters), Bay of Santos, Brazil (Marcus), Caribbean Sea (Osburn), and Magdalena Bay, Lower California (Osburn). In the Hancock collections it occurred commonly along shore and about the islands of southern California, and was dredged also at the following stations: 132-34 and 924-39, Socorro Island; 155-34, Albe- marle Island, 170-34, Chatham Island and 179-34, Bartholomew Island, Galapagos; 411-35, Gorgona, Colombia; and 531-36, San Francisquito Bay, Lower California. Also, Gulf of Panama, Galtsoff collection on pearl oysters. 14 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Division II MALACOSTEGA Levinsen, 1909 This Division, according to Levinsen, is “characterized by retaining the original frontal membrane in its primitive form and by having the operculum incompletely differentiated from this membrane.” Harmer (1926:187) includes the families Scrupariidae, Membraniporidae, Flus- tridae, Onychocellidae, and Lunulariidae. Bassler (1935 :22-25) removes the Onychococellidae and Lunulariidae to the Coilostega and separates out from the Membraniporidae the following families: Electrinidae d’Or- bigny, Hincksinidae Canu and Bassler, Alderinidae Canu and Bassler, Hiantoporidae MacGillivray, and Arachnopusiidae Jullien. It is quite apparent that much more study will be required before a completely satisfactory classification can be established. The great diffi- culty in arriving at a proper taxonomic arrangement lies in the fact that usually we cannot as yet determine the evolutionary relationships between groups of species, and this difficulty extends throughout the whole phylum. In the Malacostega it has generally been assumed that the genus Membranipora is basic because of its simplicity, though recently Harmer (1926:197) and Silen (1942:55) have given the Scrupariidae a more primitive position. It is true that in the genus Membranipora (sens. str.) there is a vestigial cryptocyst and gymnocyst, no true spines, no avicularia and no ovicells, but at the same time it has as a special character, a twinned ancestrula. In the Scrupariidae the zoarium is erect and the zooecia are tubular, which may be the primitive form of the zooecium and they also lack avicularia and spines. On the other hand Scruparia possesses hyperstomial ovicells which appear to be a specialization. Has Membranipora become secondarily simplified by the loss of structural characters? Has Scruparia developed a hyperstomial ovicell similar to that of other cheilostomes by parallel evolution? Are the tubular zooecium and erect zoarium primitive as Silen argues; what evidence we have from paleontology appears to be against it. This is a sample of the numer- ous problems involved in bryozoan taxonomy and at present the best we can do is to list the families and genera in what appears to be the order of complexity as a mark of increasing specialization. Key TO THE FAMILIES OF THE DIVISION MALACOSTEGA 1. Zoaria erect, uniserial or biserial, no avicularia. . . Scrupariidae Zoaria usually encrusting; if otherwise they are multiserial. . . 2 . Ovicells entirely absent. . . . wl el 48 Si Ovicells present, hyperstomial or endazeoccnll eonile tbs. Soman 3. Gymnocyst wanting or very slightly tay ta . Membraniporidae Gymnocyst well developed. . . . . «. » « Electrinidge No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 15 4) -Ovieell endozooecial....) 5. . <2. . (~ -s Hineksinidae Ovicell hyperstomial. . : + hea 5. Frontal membrane exposed, nae eS by a | pericnse, mrs is Frontal membrane more or less covered by a Lia appearing like an ascophoran. . . Pe 6. Ovicell elevated, a wide- -open hood; Sve rim Aba aud flared outward; strong distal spines. . . nes, Ge Chapperiidae Ovicell more complete; mural rim not flared outward; spines vatiaple. % <0 4% : . Alderinidae 7. Pericyst developed from an ialaecd ae ean ih 2 to 4 cen- tral pores. . . . «oe «2 vt, .Atantopordze Pericyst with numerous aS Taree sas . . . . . Arachnopusiidae Family Scrupariidae (Busk, 1852), Harmer, 1926 Busk established the family Scrupariidae for Scruparia, but included also the genera Hippothoa, Aetea, and Beania which are quite unrelated even to each other. Harmer (1926:197) limits the family to the genera Scruparia, Eucratea (Gemellaria), and Brettia. “The family is characterised by the erect, frequently uniserial habit of its members, by the tendency of the zooecia to have a tubular form (perhaps a primitive feature), and by the correlated restriction of the opesia to a part of the frontal surface. Hyperstomial ovicells occur in some species, but there is no evidence that avicularia have been evolved in the family” (Harmer, 1926:197). KEY TO THE GENERA 1. Zoarium with a creeping base and erect branches; zooecia uni- serial; budding at the distal end and on the frontal im- mediately proximal to the oo ovicell au on a dwarfed zooeclum. . . . . “a: tou Seruparda . Zooecia uniserial, budding deuallyes in pairs on the dorsal side at the distal enue: oe- .oa eay-s » A Brett 3. Zooecia biserial, back to back; fetches d arise seeeh the sides of the zooecia near the distal end. . . . . . . . Eucratea Genus SCRUPARIA Oken, 1815 Zoarium primarily creeping, adnate to algae and stems of hydroids and other Bryozoa, etc., but erect branches are often abundant. Zooecia tubular, nearly transparent, narrow at the proximal end where they are often slightly wrinkled, widening gradually toward the distal end. The 16 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 oval opesia occupies about half of the frontal surface. No avicularia. Ovicell hyperstomial, borne on a somewhat reduced zooecium. Genotype, Sertularia chelata Linnaeus, 1758. Scruparia ambigua (d’Orbigny), 1841 Plate 1, fig. 5 Eucratea ambigua d’Orbigny, 1841: pl. 3, figs. 13-17; 1847:11. Eucratea chelata, Robertson, 1905 :248. Eucratea chelata, O’ Donoghue, 1926 :42. Scruparia chelata, Hastings, 1930:702. Scruparia ambigua, Hastings, 1941 :470. Zoarium creeping, with erect branches; the creeping base consisting of zooecia (no stolon). The proximal end of the zooecium is tubular and gradually expanding; the opesia occupying one-third to one-half of the zooecial length and nearly parallel to the dorsal surface. Budding takes place either dorsally at the distal end or frontally immediately proximal to the opesia, the latter giving rise to erect branches. The ovicell is hyperstomial, the fertile zooecium only slightly re- duced. This species has been much confused with S. chelata (Linnaeus) and Dr. Anna B. Hastings has pointed out the differences (1941). In chelata stolons are present, the opesia is set at a rather sharp angle to the dorsal wall, the zooecia are shorter and not so slender, and the fertile zooecia are more modified, with a much reduced opesia. D’Orbigny described the species from the Falkland Islands (Iles Malouines), and Hastings shows that it has a very wide distribution around the world. Robertson recorded it as Eucratea chelata from the coast of southern California; Hastings listed it from the Galapagos Is- lands; O’Donoghue found it at Union Bay, Vancouver Island region, which is the northernmost record for the Pacific coast. In the Hancock collections it is a common form about the islands off southern California and along the coast of the mainland, from low tide mark down to 150 fathoms. Genus BRETTIA Dyster, 1858 The zoarium is erect and branching, the branches usually arising in pairs near the distal end on the dorsal side of a zooecium and facing in the same direction. The zooecia are uniserial, subtubular and elongate, with the opesia subterminal. In the genotype (B. pellucida Dyster) there are small spines, but this is not a constant character in the genus. No ovicells nor avicularia. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 17 Brettia pellucida Dyster, 1858 Brettia pellucida, O'Donoghue, 1923 :17. Zoarium erect. he zooecia are transparent, chitinous, tubular, narrow at the base and rather evenly enlarged toward the distal end which is somewhat rounded. The opesia is parallel with the frontal surface, near the distal end, and is surrounded by 6 or 8 short spines which bend somewhat over the aperture. Daughter zooecia arise singly or in pairs from the distal end of the dorsal side. O’Donoghue has recorded this species from Northumberland Chan- nel and Departure Bay, British Columbia. Otherwise it is known from England. It did not appear in the Hancock collections. Brettia tubaeformis Hincks, 1880 Brettia tubaeformis, O’ Donoghue, 1923 :17 and 1926 :42. The zoarium is erect, attached by radicles. Zooecia transparent, tubular, somewhat trumpet-shaped with a rounded opesia set at an angle to the axis of the zooecium. The aperture is surrounded by 8 or 10 short spinules which do not bend over the opesia. Hincks recorded the species from the British Isles. O’ Donoghue lists it from Cape Ebenshaw, Cape Lazo, and Ruxton Pass, British Columbia. Not taken in the Hancock collections. Genus EUCRATEA Lamouroux, 1812 Gemellaria, Savigny, 1826, of most authors. Harmer (1923:307 and 310) has straightened out the synonymy of this genus and indicates that Gemellaria loricata (Sertularia loricata Lin- naeus, 1758) is the genotype. There is a question whether this genus should be placed in the Scru- pariidae, but its presence in any other known family would be even more questionable. Eucratea loricata (Linnaeus), 1758 Plate 1, figs. 6 and 7 Sertularia loricata Linnaeus, 1758: 815. Gemellaria loricata, Hincks, 1884:3. Gemellaria loricata, Robertson, 1900 :224. Gemellaria loricata, O’ Donoghue, 1923 :17. 18 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 The zooecia occur in pairs, back to back, and branches arise from the sides of the zooecia near the distal end. ‘The proximal end of the zooecium is tubular and gradually expanding, the opesia occupies about half the zooecial length and slopes downward to the distal rim. There are no ovicells, spines nor avicularia. The zoaria form bushy colonies sometimes nearly 100 mm in height, of a light yellowish color. It is circumpolar in distribution and ranges down the Atlantic coasts of Europe to France and to Cape Cod in North America. On the Pacific coast it extends to southern British Columbia. Furthermore, Marcus (1937 :31) has taken it at Santos, Brazil, the only positive record for the southern hemisphere, and Norman (1909:238) reported it questionably from Madeira. Hincks and O’Donoghue listed it from a number of localities in British Columbia, Robertson from Prince William Sound and Juneau, Alaska, and Osburn (1923) from Point Barrow, Alaska. In the Hancock collections there are specimens from Kodiak, the Pribilof Islands and Point Barrow, Alaska. Family Membraniporidae Busk, 1854 There has been much dispute in regard to this family and it is difficult to draw a diagnosis. In general the simplicity of its members is the most striking character. The opesia is nearly as large as the zooecial front and the frontal membrane covers the whole surface; the gymnocyst is want- ing or much reduced except in Desmacystis; the cryptocyst varies from scarcely discernible to filling half of the opesia; ovicells are entirely wanting; avicularia are wanting in most of the species, but incipient vicarious avicularia, little modified and as large as the zooecia, are found in a few species; in Desmacystis there is a median frontal avicularium, and in Cupuladria there are highly specialized vibracula. Mural spines are wanting, but tubular processes or low tubercles may be present at the distal corners. Key TO THE GENERA OF MEMBRANIPORIDAE 1. Zoarium free, cupuliform, long vibracula present. . . Cone Zoarium attached, encrusting or erect. . . ; Z 2. Gymnocyst covering proximal half of zooecium, a amedian avicu- larium proximal to the opesia. . . ~ a « » Desmacystis Gymnocyst wanting or little peeelanedal : : aS 3. Triangular open areas, or triangular or rounded knobs on the basal corners, developed on a small gymnocyst. . . Conopeum No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 19 Knobs or tubular spines, if present, developed usually by the folding of the distal rim, gymnocyst usually wanting. . . . . : . Membranipora Genus MEMBRANIPORA Blainville, 1830 Biflustra d’ Orbigny, 1852. Nitscheina Canu, 1900 (Nichtina by error, according to Canu). Acanthodesia Canu and Bassler, 1920. Blainville erected the genus Membranipora to include 6 species all of which, except membranacea Linnaeus, have been placed elsewhere, leav- ing membranacea as the genotype. Canu, under the impression that Membranipora was not properly founded, replaced it by Nitscheina (Nichtina by a printer’s error) with M. membranacea as the genotype. Biflustra d’Orbigny was not figured; the description is unrecogniz- ' able, was apparently meant to include bilaminar forms, and has been discarded. Canu and Bassler separated Acanthodesia from Membranipora or Nitscheina (Nichtina) by the following diagnosis: “No ovicell. The opesium is garnished laterally by small spinous processes and inferiorly by a serrate denticle. Fifteen tentacles.” The description was based on Flustra savartii Audouin as the genotype and no other species included. Since 1920 Canu and Bassler, Harmer, Hastings, Marcus and Osburn have added numerous species with the lateral cryptocystal spinules. Borg (1931:1-30) has thoroughly investigated the status of Flustra membranacea Linnaeus and the species with which it was confused by older authors and concludes that Membranipora is a good genus with membranacea, as now understood, as the genotype, an opinion with which the present writer is in accord. With Biflustra and Nitscheina discarded, the only question that re- mains is that of the status of Acanthodesia and, frankly, I am unable to draw any definite line between Membranipora and Acanthodesia, though if there were not a continuous series of intergradations between membra- nacea and savarti the distinction would be clear enough. . Both species have twinned ancestrulae. Mural spines are wanting in both. The gymnocyst is wanting or vestigial. The cryptocyst is well developed in savarti and barely visible in membranacea, but other species show all the intermediate conditions and the proximal dentate tooth of savarti is frequently wanting on both WN 20 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 the erect and the encrusting stages. The spinules margining the inner edge of the cryptocyst are variable in the extreme; rarely seen in membranacea; in other species there may be a few small ones, a few larger ones, or they may be numerous along the sides to the level of the operculum; sometimes they fringe the edge of a broad crypto- cystal shelf. 5. The generic description of 4 canthodesia indicates only two differential characters, the proximal dentate tooth and the lateral cryptocystal spinules, both of which are frequently wanting on the erect stage and especially on the encrusting stage of the genotype 4. savarti. Further- more the erect character of savarti cannot be considered of much importance since the zoarium is often broadly encrusting and some other species which have been placed under Acanthodesia may rarely develop bilaminate folds or frills. As a result of the above analysis I feel obliged to return the species of Acanthodesia to Membranipora. It is a question of retaining Mem- branipora for the whole series or of placing them all under Acanthodesia, unless some more positive differential character can be determined. As Membranipora appears to be properly established, 4canthodesia must go into synonymy. Key TO SPECIES OF Membranipora 1. Cryptocyst narrow or wanting. . 2 Cryptocyst better developed, ae) exeenaine: faced roan the aperture. . . Bae 2. Cryptocyst wanting, rarely a | trace; tubular distal short spine) ous processes. . . . . . membranacea Cryptocyst present forming ¢ a narrow ; shelf, BO MTN i 5 3. Cryptocyst smooth; no tubercles ; thick brownish Sa juchoeiees Edges of cryptocyst serrate. as . 4 4. Frontal membrane with chitinous animales. idigeall spines long, acute, the bases often calcified. . » o #5) elles Only the distal spines present, short and eubulan . . serrilamella 5. Distal tubercles heavily calcified, often fused across the middle, sometimes spine-like. . . . « « «| « tubercubara Tubercles, if present, low rounded: noe: : 6. A flat shelf extends inward from the edge of the descendina! cryptocyst., «1. bonis (ee The descending parecer only, meh a few spinnles: aan § Las 7. Cryptocyst very broad and evenly developed on the sides, sae long, evenly distributed spinules. . . . . . hastingsae Cryptocyst broad proximally, very re a spinules of various sizes and forms. . . . Sh Geet) PENS ORAien Rebeneares NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 21 8. Zoarium encrusting only, a pair of low distal tubercles, opercul- um with dark brown border. . . cee is Zoarium erect from encrusting base; no paleecles! a pete: a9 9. Erect part of zoarium forming complex bilaminate frills, zooeci- al walls thin, proximal cryptocyst narrow. . . . perfragilis Narrow, ligulate or forked, bilaminate erect branches, or en- crusting; proximal shelf broader, walls heavier. . . . savarti Membranipora membranacea (Linnaeus), 1767 Plate 1, figs. 8 and 9 Flustra membranacea Linnaeus, 1767 :1301. Membranipora membranacea, Hincks, 1884:11. Membranipora membranacea, Robertson, 1908 :267. Membranipora membranacea, O'Donoghue, 1923 :26. The zoarium encrusts almost any object that will afford attachment, though the surfaces of the broader algae are the usual habitat and here the colonies may cover several square inches. The zooecia are very simple in structure, especially in younger and rapidly proliferating colonies. Characteristically they are elongate-quadrate and straight, with very thin walls and the opesia occupy the whole frontal surface. ‘The gymnocyst and cryptocyst are wanting (vestigial) and there are no avicularia and no ovicells. At each distal corner there is usually a knob or process which appears to be formed by a fold of the terminal wall as the distal side is membranous in younger stages. Occasionally these knobs may be pro- duced into hollow tubes or pointed short spinous processes. Not infre- quently there appears on the frontal membrane, a tall membranous tube, as much as 0.50 mm high, closed at the end, the “tower cells,” or “Thurmzooecien” of Nietsche. What may be the function, if any, of these structures, unique among the Bryozoa, is still a question, though they may be homologous with the large chitinous spines of M. villosa. CPI 1, fig. 41): It has been reported from various regions around the world, though with what certainty it is difficult to determine. Definitely it occurs on the coasts of Europe, along the Atlantic coast of North America south to the Caribbean Sea, and on the Pacific coast. It is fairly common along the shores of southern California. Hincks listed it from the Queen Char- lotte Islands and O’Donoghue from Ucluelet, British Columbia, and Robertson recorded it from Alaska, Puget Sound, and California. Hancock Stations: 1370-41 and 1406-41, Catalina Island, California, and 287-34, Cedros Island, Lower California. Abundant on the larger frondose algae along the California coast. 22 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Membranipora villosa Hincks, 1880 Plate 1, figs. 10 and 11 Membranipora villosa Hincks, 1880a:84. Membranipora villosa, Robertson, 1908 :268. Membranipora villosa, O’ Donoghue, 1923 :26; 1926 :29; 1926:250. The zoarium is encrusting, especially on the larger kelps, the colonies often coalescing to cover considerable areas. The zooecia are of moderate size, thin-walled; the gymnocyst is wanting or limited to the proximal corners ; the cryptocyst narrow proximally and laterally, finely crenulate and often with a few minute spinules; the opesia occupying practically all of the front. A characteristic feature is the chitinous spinules; minute spinules arise on the frontal membrane almost anywhere except on the operculum; slightly larger ones, often nearly as long as the width of the zooecium, arise just within the lateral margins; a still larger and heavier spine is located at each proximal corner, and one still larger, 0.50 mm or more is frequently found in a median position. All of these spines are elongate-acuminate, the basal ones sometimes forked, and without calci- fication except the bases of the larger ones in the proximal corners. The development of this species has been well discussed by Robert- son (1908:269-275) and O’Donoghue (1926a:249-261). There is a twin ancestrula, the earlier zooecia are somewhat hexagonal in form, but the later zooecia are elongate-quadrilateral much like those of M. membranacea and the spinules are less marked, often nearly wanting on the later zooecia. Hincks described the species from California; Robertson listed it from Puget Sound to San Diego, California, and O’Donoghue from numerous British Columbia localities. It did not occur in the Hancock dredgings but it is abundant on the kelps all along the California coast. Membranipora serrilamella new name Plate 1, figs. 12 and 13 Membranipora membranacea form serrata Hincks, 1882 :469. Membranipora serrata, Robertson, 1908 :268. Membranipora serrata, O’ Donoghue, 1923 :26; 1926 :29. Conopeum serrata, Okada, 1929:11. Membranipora serrata, Okada, 1934 :4. A canthodesia serrata, Marcus, 1937 :44. (Not Membranipora serrata MacGillivray, 1868 :6). NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 23 Zoaria encrusting, especially on the broader algae where the colonies often coalesce to cover nearly the whole frond. The zooecia are of moderate size, about 0.50 mm long by 0.20 to 0.25 mm wide, usually not so regularly elongate-quadrate as in M. membranacea but otherwise re- sembling that species. The walls are thicker and there is a narrow crypto- cyst on the proximal and lateral sides which is irregularly serrated with short laterally directed spinules ; there is often a somewhat longer spinule at the proximal end. There is consistently a short hollow spine or pro- tuberance at each distal corner, developed by the folding of the distal rim; in older stages of calcification these spines may become closed at the tips. The ancestrula is twinned like that of Md. membranacea. Hincks’ specimens were from Virago Sound, British Columbia; Rob- ertson records it from Puget Sound to southern California; O’Donoghue lists it from numerous localities in British Columbia; Marcus found it at several localities in Brazil, and Okada records it at a number of places in Japan. The form which Hastings listed as Acanthodesia ser- rata from Balboa, Canal Zone, belongs elsewhere (see under Membrani- pora hastingsae n. sp.). The name serrata as applied to this species is preoccupied by Mem- branipora serrata MacGillivray, 1868:6, and a new name is necessary. Excessively abundant on the floating fronds of kelp and dredged on a few occasions down to 10 fathoms. Membranipora tuberculata (Bosc), 1802 Plate 2, figs. 4, 5 and 6 Flustra tuberculata Bosc, 1802 :143. Flustra tehuelcha d Orbigny, 1839-46 :17. Membranipora tehuelcha, Robertson, 1908 :265. Nichtina tuberculata, Harmer, 1926:208. Nichtina tuberculata, Hastings, 1930:706. Membranipora tuberculata, Osburn, 1947 :9. This is the well-known ‘“Gulfweed” bryozoan which Bosc described as occurring “‘en immense quantité sur les fucus nageans sur |’Atlantique.”’ The zoarium forms a white lace-work on Sargassum floating over the wide oceans and occurs on attached algae along shore in warmer waters. The zooecia are quadrangular, but shorter and wider than in M. mem- branacea and the walls are much more heavily calcified. Characteristi- cally there is a pair of tubercles at the distal corners, which appear to be formed as folds of the distal rim as they are open and covered by 24 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 membrane on the distal side. They are very variable, frequently fusing across the end of the zooecium and occasionally they are cornuate, ex- tending forward with the points curved toward each other, and more rarely a third tubercle is developed between these in the midline. A short gymnocyst is sometimes present and the cryptocyst, with lateral spinules is usually well developed at the proximal end. Found wherever Sargassum drifts over the warmer seas; along shore on the Atlantic coast from North Carolina to Brazil; on the Pacific coast from California to Peru and the Galapagos Islands; southern Japan, Indian Ocean and the East Indies. Dredged in shallow water, usually on algae, by the Hancock Expedi- tions at numerous stations from California to Peru. Membranipora perfragilis (MacGillivray), 1881 Plate 2, fig. 8 Biflustra fragilis MacGillivray, 1869 :138. Biflustra perfragilis MacGillivray, 1881:27 (changed the name). Membranipora perfragilis MacGillivray, 1895 :39. Membranipora crassimarginata var. erecta Busk, 1884 :63. Membranipora perfragilis, Hincks, 1884 :278. Amphiblestrum perfragile, Ortmann, 1890 :29. Membranipora serrata, Robertson, 1908 :269 (in part). Acanthodesia perfragilis, Hastings, 1945 :98. The zoarium encrusting and rising free into richly convoluted or frilled and variously contorted masses, the frills often anastomosing ; bi- laminar, the layers back to back, but occasionally one layer may extend slightly beyond the other. In the free frills the zooecia are regularly dis- posed, quite regular in form, the lateral walls parallel, the distal wall arcuate; 0.50 to 0.60 mm long by 0.25 to 0.30 mm wide. The zooecia of the encrusting base vary greatly in size and proportions, sometimes being as wide as they are long. The mural rim is finely crenate, the distal as well as the lateral walls. The cryptocyst is distinct, narrow on the sides but continued around the distal end of the opesia; usually broader at the proximal end, but sometimes limited to the proximal corners. There are incipient interzooecial avicularia, smaller than the zooecia, with a spatulate mandible which is without pivot. They appear to be rare and I have found them only on the encrusting base. It is recorded as common in Australian waters and is known also from Japan. Robertson (1908:269), under M. serrata, reports of that No. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 25 species, “at Monterey, California, it occurs free, very much folded and contorted foliaceous masses,” and it seems probable that these specimens were perfragilis. A remarkable colony, shaped like a large pompon, was collected in shallow water at San Pedro, California. The zoarium measures about 140 mm in length by 100 mm in width and height, and is remarkably convoluted. It is attached to a large pebble, the encrusting base being more than half as wide as the erect portion and spreading down over the sides of the pebble. The specimen is deposited in the Cabrillo Beach Marine Museum of the City of Los Angeles and the author is indebted to Dr. W. L. Lloyd, Director of the Museum, for the privilege of study- ing the specimen. Some fragments of the zoarium are deposited in the Hancock collections. Membranipora fusca new species Plate 1, fig. 14 Zoarium encrusting on shells and stones, covering considerable areas ; at first the thick ectocyst is clear, then the operculum develops a heavy dark border and later the whole ectocyst becomes yellowish brown, then darker to nearly black. The zooecia are moderate in size, usually ranging between 0.50 and 0.70 mm in length and 0.30 to 0.45 mm in width, the opesia occupying nearly all of the front; a narrow brown line separates the zooecia even in younger stages. The descending cryptocyst is broadest at the proximal end and continues more narrowly along the sides, finely granulated and without spinules. The basal gymnocyst is only wide enough to bear a pair of transversely elongate low tubercles, which in final calcification may fuse in the midline or become heavy rounded knobs. The operculum is semicircular, about 0.20 mm in width, heavily chitinized like the frontal ectocyst and with a conspicuous black border. Multiporous septulae are present in both the lateral and distal walls. No spines nor avicularia and no ovicells. Type, AHF, no. 9. Type locality, Mussel Point, northern California, 36°37’20” N, 121° 54’15”W. Also at Del Monte, California, 36°37/00”N, 121°53’00”W, intertidal to 6 fms, collected by Miss A. E. Blagg and Dr. R. L. Bolin, numerous colonies; also at Tomales Bay, California, 5 fms (Osburn). 26 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Membranipora tenuis Desor, 1848 Plate 2, figs. 9 and 10 Membranipora tenuis Desor, 1848 :66. Membranipora denticulata Busk, 1856:176. Biflustra denticulata, Smitt, 1873 :18. Hemiseptella denticulata, Canu and Bassler, 1928 :62. Acanthodesia denticulata, Hastings, 1930 :707. The M. denticulata of Busk from the Pacific coast and the Biflustra denticulata of Smitt from the Atlantic are definitely the same species and the same as the tenuis of Desor, according to Dr. Anna B. Hastings (in litt.) who has examined Busk’s type material and a large number of other specimens in the British Museum from various Atlantic and Pa- cific localities. Zoarium encrusting anything that affords attachment, but most com- mon on shells and stones; occasionally rising in free, bilaminate frills similar to those of M. perfragilis but more delicate. The zooecia are moderate in size, 0.45 to 0.50 mm long by 0.20 to 0.25 mm wide, but often with a much wider range. The walls are moderately high and the mural rim roughly and irregularly granulated; usually there is no evi- dence of a gymnocyst; the cryptocyst is well developed and exceedingly variable, proximally it forms a broad shelf which extends more narrowly along the sides and then becomes somewhat broader around the distal border. Occasionally the shelf may fill in the whole basal half of the opesia, or it may be limited to a narrow band; the border of the shelf bears very irregular and sometimes branched spinules, which may extend laterally half way across the opesia or the border may be merely irregu- larly serrate. The proximal shelf is flat and smooth except for a few to many minute tubercles. The ectocyst is slightly brownish and often there is a distinct brown line separating the mural rims. The operculum is slightly more heavily chitinized than the frontal membrane and has a thick brown border; width 0.13 mm. No ovicells, no avicularia, no spines, no dietellae. Small rough processes may occur at the proximal corners, but these are extremely variable in size and occurrence. The variations in zooecial size and form, the extent of the cryptocyst, and the presence or absence of the tubercles have led to the description of several supposed new species; Membrani- pora danica Levinsen, from Denmark, and Hemiseptella africana, H. hexagonalis and H. grandicella of Canu and Bassler appear certainly to belong under tenuis. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 27 It is an abundant species along the Atlantic coast from Cape Cod to Brazil, in shallow water along the shores and entering estuaries where the salinity may be reduced to less than one-half that of sea water. It does not appear to be as abundant anywhere on the Pacific coast. Busk’s material of denticulata came from Mazatlan, Mexico, and Hastings recorded it from several localities in the Canal Zone and from the Ga- lapagos Islands. Probably because it is a shallow water species it did not appear frequently in the Hancock dredgings, as it was not taken below 16 fathoms. Fairly common along the coast of southern California and down the west coast of Lower California; at Stations 1044-40 (Tiburon Island), 1049-40 (Angel de la Guardia Island) and 1071-40 (San Felipe Bay) in the Gulf of California; Station 374-35 at Independencia Bay, Peru. Also at Acapulco Bay, Mexico, specimens collected by Captain F. E. Lewis. Membranipora savarti (Audouin), 1826 Plate 2, fig. 7 Flustra Savartii Audouin, 1826 :240. Biflustra Savartii, Smitt, 1873 :20. Acanthodesia savartii, Canu and Bassler, 1920:100; 1930:4. Acanthodesia savartii, Marcus, 1937 :40. Acanthodesia savarti, Osburn, 1947 :9. The zoarium is erect, with narrow ligulate or bifurcate bilaminate fronds rising from an encrusting base which may spread over an area of a square centimeter or more. The zooecia of the erect fronds are regularly elongate-quadrangular, moderate in size, the walls rather heavily calci- fied and granulated. The cryptocyst forms a horizontal shelf at the proximal end with a denticulate process projecting into the opesia, and there are also denticles projecting from the narrower lateral cryptocyst. The proximal horizontal dentate process of the cryptocyst is a very striking character when it is present, and the genus Acanthodesia was founded on it. However it is very often wanting entirely, or present on only a few zooecia of a colony. I have failed to find any evidence of it in Pacific coast specimens which otherwise agree perfectly. On the other hand, Silen (1941:19) found “the proximal denticle prominent in all specimens” from the Bonin Islands, Japan. It is a common species around the world in warmer shallow waters. Dredged at 14 Hancock stations: off Point Loma, California; Tibu- ron Island, Gulf of California; Lower California at Dewey Channel 28 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 and Fraile Bay; Port Culebra, Costa Rica; Secas Islands and Bahia Honda, Panama; James, Hood, Indefatigable and Chatham Islands, Galapagos, the greatest depth being 40 fms. Membranipora pachytheca new species Plate 2, figs. 2 and 3 Zoarium encrusting shells, white in the young, brownish in color when fully developed. The zooecia are large (average about 0.85 mm long, but ranging from 0.65 to 1.10 mm, and in width ranging from 0.45 to 0.65 mm); ellipsoid with the distal end evenly rounded and slightly elevated; distinct; the walls very thin; opesia occupying all of the front; no evident gymnocyst; a slight horizontal cryptocyst, usually in the proximal corners but often there is no evidence of it. The mural rim is smooth and exceedingly thin, there is no evidence of a descending cryptocyst and the horizontal cryptocyst is minute and perfectly smooth. The frontal ectocyst is thick, pale brownish, and covers the whole of the frontal surface, forming a thin brown line above the adjoining mural rims and continued more heavily around the distal end of the zooecium. The operculum is heavily chitinized and brownish in color, slightly arcu- ate in cross-section, very large (0.25 to 0.30 mm in width by 0.25 to 0.30 mm in length) thinner at the edges, with a sclerite on either side a little way within the margin. In the side walls there are 4 multiporous rosette plates, while in the distal wall there are numerous single pores which form a band across it at its middle. The tentacles are numerous, about 20. There are no avicularia and no ooecia; developing ova can be observed in the body cavity. This is an unusual appearing species, looking at first sight like an encrusting 4/cyonidium ; on being calcined the thin walls and large opesia suggest 4 plousina but there is no evidence of endozooecial ovicells. The negative characters, such as the absence of the gymnocyst, the vestigial cryptocyst, the absence of spines, denticles, avicularia and ooecia, the re- duced calcification and the nature of the communication pores all appear to indicate Membranipora as the proper genus. The most striking characters are the large, arched, leathery opercul- um, the rounded distal ends of the large zooecia and the unusually thin walls. Type, AHF no. 10. Type locality, Canoe Bay, Alaska, 40 fathoms, on shells, several colonies, one more than an inch across (Alaska Crab Investigation). NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 29 Membranipora hastingsae new species Plate 2, fig. 1 Acanthodesia serrata, Hastings, 1930:707. Zoarium encrusting. The zooecia are moderate in size, elongate and quite regularly quandrangular in form; walls very thin. The most characteristic feature is the very extensive development of the cryptocyst, which extends broadly on the sides to the level of the operculum, with numerous elongate spinules, rather evenly spaced, which nearly meet across the opesia and which occur on the entire lateral cryptocyst as far as to the operculum. The polypide chamber is thus almost enclosed beneath the cryptocyst and its horizontal spinules. At each corner there is a triangular area which appears to occupy all of the gymnocyst and which develops into a nodule, according to Hastings, or a short spine. Dr. Hastings has described incipient avicularia of the same size as the zooecia and possessing a polypide, but with a greatly enlarged and somewhat modified operculum. The small specimen in my possession does not show the avicularia, but otherwise the agreement with her de- scription and excellent figures (Plate 4, figs. 13-15) is perfect. Dr. Hastings was evidently in error in listing this form under the serrata of Hincks for the following reasons: (1) the cryptocyst is re- markably broad and evenly developed on the sides and extends to the distal wall, where it leaves only space for the operculum (in serrata the cryptocyst is always narrow) ; (2) the spinules are long, extending nearly or quite to the median line, very equally developed and evenly spaced to the opercular area (in serrata the edge of the cryptocyst is crenate, with occasional shorter denticles irregularly distributed) ; (3) the spines at the corners are much less developed than in serrata. Furthermore I have examined large numbers of serrata and found no evidence of “incipient avicularia.” It is a pleasure to name this species for Dr. Anna B. Hastings of the British Museum of Natural History, who has done so much to further our knowledge of the Bryozoa. The type material consists of a single colony from Balboa, Canal Zone, sent to me for identification by the William F. Clapp Laboratories of Duxbury, Massachusetts. Dr. Hastings recorded it as Acanthodesia serrata, also from Balboa “docks, buoy and shore.” Type, AHF no. 11. Type locality, Balboa, Canal Zone. Also from Perlas Islands, Gulf of Panama, F. H. Bradley, collector. 30 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Genus CONOPEUM Gray, 1848 This genus is especially characterized by the development of triangu- lar cavities on the surface of the gymnocyst at its proximal corners (‘“‘interopezial cavities’). In the early growth of the zooecium the small gymnocyst is smooth, then calcified walls begin to enclose a triangular space, sometimes in each basal corner, sometimes in only one corner, and very frequently they may be wanting over a large portion of a colony. As calcification becomes complete, triangular or rounded knobs, with a small membranous aperture, are formed. These may even become closed and also they may be fused across the basal part of the zooecium to form irregular quadrangular lumps or knobs. Avicularia and mural spines are wanting. (See Marcus 1937:36, and Osburn 1940:350). Genotype, Flustra lacroixii Audouin, 1826. Conopeum commensale Kirkpatrick and Metzelaar, 1922 Plate 2, figs. 12, 13, 14 and 15 Kirkpatrick and Metzelaar, 1922 :985. Marcus, 1937 :35, 1938:16, 1939:126 (discussion). The zoarium usually encrusts shells, especially gastropod shells in- habited by hermit crabs; white in earlier stages, becoming yellowish and finally brown; multilaminar. The zooecia are rather regular in arrangement, roughly quadrangu- lar or elongate-hexagonal, the outlines marked by a very distinct dark brown line. The membranous ectocyst covering the frontal surface is thickly studded with chitinous, villose spinules, especially around the border; these spinules are semierect, pointed toward the center of the zooecial area, and do not occur on the mural rim. The zooecial walls are heavily calcified and the mural rim as well as the descending crypto- cyst is granulated. The opesia is ovoid in form and the operculum well chitinized, with a somewhat heavier border, yellowish in color. Originally found at a number of localities in northwest Africa. Mar- cus (1937:36) records it from various places in Bahia de Santos, Brazil, and gives an excellent account of it. There is much variation in the form of the tubercles and they may be single or double, large or small, and may often be wanting over con- siderable areas of a colony. The chitinous ectocystal spinules also show much variation, usually numerous in our material, but sometimes want- ing altogether. Kirkpatrick and Metzelaar did not mention them in No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 31 their description, but a specimen from Cape Blanco, West Africa, the type locality, received through the kindness of Dr. Anna B. Hastings of the British Museum, shows a very few delicate, almost transparent spinules. The Hancock Expeditions recovered this species from off Guaymas (Station 1092-40) and Tepoca Bay (Station 1078-40), Sonora, Mexico; Santa Maria Bay, Lower California (Station 1031) ; Cocos Bay, Costa Rica (Station 116-33), and La Plata Islands, Ecuador (Station 212-34). Dr. Howard R. Hill of the Los Angeles Museum has presented the writer with a specimen from San Felipe, western Mexico. It is therefore widely distributed in warm waters along the Pacific coast from northern Mexico to Ecuador. Depth 2 to 45 fathoms. Conopeum reticulum (Linnaeus), 1767 Plate 2, fig. 11 Millepora reticulum Linnaeus, 1767 :1284. Membranipora lacroixii, Robertson, 1908 :261, (? part). Membranipora lacroixii var. triangulata, O’Donoghue, 1923 :25. Conopeum reticulum, Harmer, 1926:211, synonymy and discussion. Conopeum reticulum, Osburn, 1940 :350-352, discussion. Zoarium encrusting on various substrata. Zooecia of moderate size, usually about twice as long as the width but occasionally short and wide, usually ranging in length between 0.40 and 0.50 mm. There is a short gymnocyst (often vestigial), which typically bears a pair of triangular areas in the proximal corners. These triangular structures are at first open with a membranous covering, but later they often become closed and knob-like, or they may be fused into a single knob, often they are wanting, sometimes over considerable areas of a colony. They may be readily con- fused with the minute or vestigial avicularia of some species of Antropora but they are merely surface structures on the basal gymnocyst and are probably homologous with the basal tubercles of some species of Mem- branipora. The opesia is elliptical, oval or rounded. The walls are rather heavily calcified and the descending cryptocyst coarsely granular, sometimes with conical points projecting laterally inward. Ovicells are wanting. Small avicularia have been mentioned by some authors, but I have never been able to find them in either Atlantic or Pacific specimens and I am in- clined to believe the authors were mistaken or had some other species. In the literature up to 1926 this species was generally confused with lacroixi Audouin, and most of the references are under that specific name. 32 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Robertson’s description and figure are inconclusive; she may have had this species or Antropora tincta (Hastings), which is much more abun- dant on the southern California coast, or both of them. O’Donoghue’s record from British Columbia is probably correct for his variety triangu- lata, but the varieties paucispina and multispina doubtless refer to some other species, probably Electra crustulenta (Pallas). This cosmopolitan species has been somewhat doubtfully recorded from Alaska to southern California, where Robertson states that it is “quite abundant.” It did not appear in the Hancock dredgings, but the writer has ob- served it in shore collections at Monterey Bay, Newport Harbor, and La Jolla, California. Mr. R. J. Menzies collected it at 5 fms in To- males Bay, California, rather common, one specimen covering more than 8 square inches of the inside of a clam shell. Apparently it is not an abun- dant species and has been taken only in shallow water. Genus DESMACYSTIS new genus Zoarium encrusting. Zooecia thin walled; an extensive gymnocyst which is strengthened by a median carina and lateral transverse ribs. Opesia broad, its side walls extended laterally above the bases of adjoin- ing zooecia. Cryptocyst apparently wanting. A median, sessile, transverse avicularium on the distal border of the gymnocyst. No ooecia; no spines; no dietellae. Genotype, Membranipora sandalia Robertson. Where to place Robertson’s M. sandalia has puzzled me greatly. It cannot remain in Membranipora since that genus, as now defined, has a very limited gymnocyst and no avicularia; Electra is suggested by the very extensive gymnocyst, but the presence of an avicularium and the total absence of spines apparently exclude sandalia from the genus; the absence of any form of ovicell seems to limit it to the simpler Membrani- poridae, but it cannot be accepted in any modern genus of that group. The Membraniporidae (sens str.) are in so much need of careful, de- tailed revision, that it is with extreme hesitation that I inject another generic description into this difficult group. Desmacystis sandalia (Robertson), 1900 Plate 3, fig. 1 Membranipora sandalia Robertson, 1900 :324; 1908 :264. Zoarium encrusting, but not closely attached, forming fan-shaped colonies of a rather rough appearance. The zooecia are large, elongate, narrowed on the proximal half, length 0.85 (0.65 to 1.00) mm, width NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 33 0.40 (0.26 to 0.50) mm. Opesia variable in form and size (0.25 to 0.50 mm long by 0.25 to 0.45 mm wide), irregularly rounded or ovate and occupying approximately the distal half of the front. The mural rim flares outward on the sides over the bases of the adjoining zooecia. The proxi- mal half, more or less, of the front is occupied by the extensive gymnocyst. When first formed this is smooth but soon a series of ribs (4 to 7 in number, with a median one which forms a sort of keel) grows inward from the border to become attached to the median keel; these ribs are apparently developed from the surface of the gymnocyst, as a part of it, and while they may have some resemblance to the costae of the cribri- morphs, they are in no sense homologous. There is no evidence of a crypto- cyst. The frontal membrane is somewhat chitinized and the operculum (about 0.20 mm broad) has a heavier brown border. The distal border of the gymnocyst bears a peculiar large, sessile, median, transverse avicularium with a short-triangular mandible which is hooked at the tip. There are no ooecia; no spines; no dietellae. Robertson described the species from Yakutat, southern Alaska, and apparently it has not been noted since. Our specimens are from Yakan Point, Queen Charlotte Islands, British Columbia, low tide, Dr. E. F. Ricketts, collector, three colonies. Genus CUPULADRIA Canu and Bassler, 1919 The name Cupularia (Cupulaire Lamouroux, 1821), used to include species of Cupuladria and Discoporella for many years, has been shown by Hastings (1930:717) to be untenable. In 1919:77 Canu and Bassler established the genus Cupuladria, with C. canariensis Busk as the geno- type, to include the membraniporid species with a wide open front. Cupuladria canariensis (Busk), 1859 Plate 3, figs. 2 and 3 Membranipora canariensis Busk, 1859 :66. Cupuladria canariensis, Hastings, 1930 :714. Zoarium free, unilaminar; shaped like a cup or saucer, varying greatly in this respect, sometimes almost plate-like, at other times quite cupuliform; usually quite circular but occasionally elliptical or distorted. The zooecia are rhomboidal, as a rule very regularly arranged, each with a long chitinous flagellum at the distal end. The opesia is large, without any trace of a horizontal cryptocyst. The walls are thin and high, with a narrow descending cryptocyst which is distinctly granulated but which never bears spinules. The vibracula are very long and rather stiff and 34 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 often move in unison and when stimulated they may stand erect for some time. The vibracular chamber is prominent and its aperture is lunate, with one side higher than the other. The vibracula and the frontal membrane, especially near the walls, are brownish in color. The dorsal side shows small quadrangular areas with usually four pores in each area. While the form of the colony and the arrangement of the zooecia are usually quite regular, exceptions are not uncommon. The larvae usually attach themselves to small objects, especially sand grains, and grow free and symmetrically beyond the edges, but occasionally they attach on larger irregular objects and become distorted. The C. elongata of Saka- kura (1935:6) is an example of the same sort of irregularity in C. guineensis (Busk). The writer has a specimen of canariensis which be- came attached to the inside of a shell where it followed the curvature of the shell, becoming concave on the frontal surface. This species appears to be limited to the Atlantic and the Mediter- ranean Sea and the Pacific coast of North America. It is an abundant form in the Gulf of Mexico, but it has hitherto escaped notice on the Pacific coast except for Hastings’ record at Gorgona, Colombia. Robert- son’s record (1908 :314) is due to a misidentification, as she undoubtedly had Discoporella unbellata (Defrance). The range of the species on the Pacific coast, as determined by the Hancock dredgings, is from Cedros (Cerros) Island, half way down the coast of Lower California, to Ecuador and the Galapagos Islands. Inter- mediate stations, more than 30, include the Gulf of California, Clarion and Socorro Islands west of Mexico, the west coast of Mexico, Costa Rica, Panama, and Colombia. It occurs in shallow water and down to 40 fathoms, but appears to be more abundant from 10 to 20 fathoms. Family Electrinidae d’Orbigny, 1851 The zoarium is usually encrusting, but may be erected from an en- crusting base. The zooecia are usually provided with a well-developed gymnocyst but this is sometimes vestigial and both extremes may some- times be seen on the same colony. There are no ovicells, no avicularia, and no dietellae. Spines are usually present around the border of the opesia, occasionally wanting, in some cases limited to a single strong median proximal spine which may be reduced to a mere tubercle or be very greatly elongated. The simple nature of the zooecia, except for the spines, relates this group to the more primitive membranipores. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 3) ELECTRA Lamouroux, 1816 Genotype, Flustra verticillata Solander, 1786:15. Key TO THE SPECIES OF Electra 1. No proximal spines, lateral ones long and numerous; the oper- culum bears a pair of long furcate, delicate chitinous spinous processes, . . . . . anomala Proximal spines present (but. see ie crustulenta var. ). ee os 2. A single median proximal spine. Serge ot cairns’, x27 pack Seer More than one proximal spine... a) hee eee 3. A single ee spine only; operculum calened hie! Paasruleats var. arctica lateral spines Piss jaresents ae ee 4. Proximal spine regularly present, serone-: 1 ic 4 ie a eee lateral spines, the distal ones erect. . . . . + hastingsae Proximal spine weak or wanting, others slender Bad varying in number, often a operculum weakly calcified. . crustulenta var. 5. A fransverse row oe eral stout proaieeal opines: a strong branched scutiform spine on each side of the operculum. . dbiscuta A long furcate spine on each side of the median proximal one, varying preatly, . 2). 5 0°... . bellula var. bicornis Electra crustulenta (Pallas), 1766 Plate 3, figs. 4 and 5 Eschara crustulenta Pallas, 1766:39. Membranipora lacroixii, O’Donoghue, 1923:25 (? part). Electra crustulenta, Borg, 1931:29. Membranipora crustulenta, Osburn, 1944:31. This species, which is common on both sides of the North Atlantic appears not to have been recorded definitely from the Eastern Pacific. The synonymy is so confused that it is not always possible to be certain of the reference. The work of Borg (1931, ““On some species of Mem- branipora’) has cleared up a great many points, especially concerning the numerous variations. The zoarium is encrusting in a thin layer, often with narrow ramify- ing branches of one to several rows of zooecia. The zooecia are rather regular in distribution, elliptical in form, and separated by deep grooves. The walls are moderately thick as a rule, finely granulated on the mural rim and narrow cryptocyst. The smooth gymnocyst is often well de- veloped, but under crowded growth conditions may be reduced to the vanishing point. The mural spines vary exceedingly, from none to as many as 6 on each side. The operculum is often more or less calcified and shows white against the rest of the frontal membrane. 36 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Dr. Borg discusses six varieties, all but one of which were once con- sidered species and in several of these the median proximal spine and the calcification of the operculum are wanting. Our specimens resemble the variety baltica in general appearance, but in the lack of the proximal spine and in the very weak calcification of the operculum they suggest the variety stammeri (See Plate 3, fig. 5). Hancock Station 1478-42, Yaquina Bay, Oregon, on shells along shore. The species has also been taken at Dillon Beach, and Monterey Bay, California. Electra crustulenta var. arctica Borg, 1931 Plate 3, fig. 4 This well-marked variety, characterized by a single strong spine in the midline proximal to the opesia, is abundant at Point Barrow, Alaska, G. E. MacGinitie, collector; at Punuk Island, Bering Sea; Nunivak Island, Nash Harbor, Alaska and south to Dillon Beach, California. Electra anomala new species Plate 3, fig. 6 Zoarium encrusting, thin and delicate. The zooecia are moderate in size, averaging about 0.50 mm in length by 0.30 mm in width, but there is a wide range in both dimensions; distinct with deep separating grooves; walls thin, the mural rim narrow and somewhat inflected, smooth or slightly granular. The gymnocyst is variable from one-fourth the zooeci- al length to almost wanting; cryptocyst not evident. The opesia is ellipti- cal, narrowed at the base of the operculum, which is well chitinized. From the middle of the front surface of the operculum arises a pair of very elongate, bifurcate chitinous spines which extend far over the base of the distal zooecium ; this anomalous condition is without parallel in the writer’s experience. At the distal end, on either side, is a short, stout, erect spine, which often appears to belong to the distal zooecium. The marginal spines are extremely variable; in the same colony the zooecia of the central area for several generations are spineless; there follows a narrow transitional zone in which there are a few spines, increasing in size and number out- ward; and finally a climax is reached with 8 to 10 long, slender spines on each side which bend low across the opesia until their points may pass each other; frequently these are briefly bifurcate at their tips, but there never appears to be any fusion of the tips. No avicularia; no ooecia; multiporous septulae are present in both lateral and distal walls. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA ‘4 | In most of its characters it resembles E. angulata Levinsen (1909: 149) from Siam, but that species has an evident cryptocyst, shorter, simple spines, and lacks the extraordinary opercular decoration of an- omala. Type, AHF no. 12. Type locality, Balboa, Canal Zone 8 colonies encrusting wood, the largest 20 mm in diameter. The specimens were received from the W. F. Clapp Biological Laboratories. Electra biscuta new species Plate 3, figs. 7 and 8 Zoarium thin, encrusting shells, the colonies small. Zooecia small (length 0.26 to 0.30 mm, width 0.18 to 0.22 mm), distinct with well-marked grooves. The gymnocyst is usually very limited, but may occupy one-fourth or more of the zooecial length; cryptocyst narrow, not expanded, smooth or finely granulated; the mural rim low, thin and slightly granulated. The distal wall is strongly arched forward on the dorsal side. The opesia is irregularly ovate, straighter on the proximal border and conspicuously narrowed in the region of the opercul- um; occasionally more elliptical. The spines are heavy, broad at the base and without joints and are of three kinds: (1) a broad spine, often cervicorn with three points, sometimes only bifid or again simply broadened; these are situated one on each side of the operculum and when fully developed bend across the opesia like a pair of scuta; (2) just distal to these on each side is a short, stout, conical, erect spine opposite the distal end of the operculum; (3) on the gymnocyst immediately proximal to the opesia is a transverse series of short, stout conical spines which project forward in a row at a slight angle above the opesia, these usually number 3 or 4 but vary from 1 to 5; often their bases are more or less fused, and their tips often briefly bifurcate. The generic relationship of this species is somewhat in doubt. No ooecia have been observed and there are no avicularia. The communica- tion pores are in the form of round multiporous rosette plates. The absence of ooecia and avicularia and the presence of a gymnocyst, mural spines and thin lateral and dorsal walls, without dietellae, suggest the genus Electra, though there is little resemblance in appearance to any others of that genus. Type, AHF no. 13. 38 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Type locality, Mazatlan, Mexico, 23°19’00’N, 106°23’00”W, inter- tidal, two colonies, Miss A. E. Blagg, collector. Also taken at Hancock Station 341, three colonies, Secas Islands, Panama, 7°53’10”N, 82°12’ 05” W, 30 fms. Electra bellula var. bicornis (Hincks), 1881 Membranipora bellula var. a (bicornis) Hincks, 1881a:149. Electra bellula var. bicornis, Hastings, 1930 :706. This is a thin-walled, rather delicate species with a small, short, median spine proximal to the opesia. The variety dicornis, in addition to the median spine, has a longer forked or branched spine on either side of the central one, bending forward over the opesia, (the median spine sometimes wanting). The species and variety have a wide distribution. It did not occur in the Hancock dredgings, but Dr. Hastings has recorded it from the Ga- lapagos Islands. Electra hastingsae Marcus, 1938 Electra hastingsae Marcus, 1938 :17, synonymy. Electra monostachys, Hastings, 1930 :706. (Not Membranipora monostachys Busk, 1854, and numerous later au- thors). This species has been confused with Electra (Membranipora) crustu- lenta (Pallas), the variety with a single proximal spine, which it re- sembles, but in that form there is a well-calcified operculum often of striking white appearance, while in hastingsae the operculum is entirely membranous. There is usually a pair of small distal spines opposite the operculum and some small marginal spines; the single proximal spine is smaller and not as much enlarged at the base as in crustulenta. This species was not found in the Hancock collections, but Hastings recorded it from Balboa, Canal Zone, along shore. It is a common species along the shores of western Europe and eastern North America, and Marcus records it from Santos Bay, Brazil. Family Flustridae Smitt, 1867 The zoarium is erect, free, frondose and flexible with little calcifica- tion (rarely encrusting and loosely attached). Zooecia membraniporine, the opesia occupying all or nearly all of the front; walls thin, usually with uniporous septules. Avicularia interzooecial, usually simple and No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 39 primitive (wanting in some genera). Ooecia, when present, endozooecial and embedded either in the base of the succeeding zooecium or in an avicularian chamber. Levinsen, 1909:122-125, and Silen, 1941 :49-54, have presented the best discussions and analyses of this family and have erected a number of new genera. Silen, 1941 :49-54, retains the old genus Carbasea Gray for species with unilaminar zoaria which lack both aviacularia and ooecia. He erects a new genus, Terminoflustra, for the species with squared avicularian chambers, which are located at the bifurcation of zooecial rows, the geno- type being Flustra barleet Busk. The genotype of Carbasea is Flustra carbasea Solander. Genus CARBASEA Gray, 1848 The zoarium is frondose with lobate branches, unilaminar. There are no avicularia and no ooecia. Carbasea carbasea (Solander), 1786 Plate 3, fig. 9 Flustra carbasea, Hincks, 1880 :123. The zoarium is usually a broad, thin, sheet, more or less subdivided into lobes, with a narrow short stalk which is attached by a narrow base. There is a single layer of zooecia, all facing the same direction. The zooecia are large, 0.90 to 1.25 mm long and about 0.40 mm wide, in quite regular alternating series, the narrow base of one between the ex- panded distal halves of those on either side; the walls thin and the distal wall strongly curved forward; opesia occupying all of the frontal area, with sometimes a slight development of a proximal cryptocyst. No spines ; no avicularia; no ovicells. The “Lawn Sea-mat”’ of Ellis and Solander’s Zoophytology is a com- mon high-northern species in the North Atlantic and adjacent Arctic Ocean. Recorded frequently from Spitzbergen south to the British Isles and west to Greenland, Osburn (1932:7) extended its range to Lou- byrne, Hudson Bay. It now appears in collections from Alaska and no doubt is circumpolar in distribution. Dall Alaska Collection 3623-1670, U. S. National Museum, and Albatross Collection, Cordova, Alaska, June 28, 1914, Common at Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, col- lector. 40 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Genus TERMINOFLUSTRA Silen, 1941 Avicularia squared and situated at the bifurcations of zooecial rows; ooecia endozooecial, embedded in the bases of the succeeding zooecia. Genotype, Flustra barleei Busk, 1860 :120. Terminoflustra membranaceo-truncata (Smitt), 1867 Plate 3, fig. 10 Flustra membranaceo-truncata Smitt, 1867 :358. Flustra membranaceo-truncata, Robertson, 1905 :292. Flustra membranaceo-truncata, O’ Donoghue, 1923 :24 ; 1926:47. The zoarium is erect and consists of irregularly flabellate fronds, unilaminar and thin. The zooecia are irregularly quadrate or elongate- hexagonal, truncate at both ends, usually narrower at the proximal end. The walls are thin, with a minute spine, often wanting, at each distal corner. The avicularia, which are rather rare, are usually situated at the bases of new rows of zooecia; nearly square in outline and about one- third as large as the zooecia; the mandible is semicircular, directed distal- ly, with a continuous chitinized border. Ooecia endozooecial, embedded in the bases of the succeeding zooecia, small, inconspicuous except in transmitted light. Circumpolar. Robertson recorded it from the Pribilof Islands, Bering Sea; O’Donoghue listed it from Banks Island and China Hat, in British Columbia waters. In studying the material from the U. S. Alaska Crab Investigation, I find two small colonies from Alitak Bay, Alaska, at 30 fms. Family Hincksinidae Canu and Bassler, 1927 This family includes membranipores of simple structure, similar to the Membraniporidae except for the presence of an endozooecial ovicell. The ovicell is usually a narrow, transverse, shallow structure, opening widely into the zooecial cavity and closed by the operculum, but sometimes it is merely a rounded expansion of the zooecial cavity into the base of the succeeding zooecium. Spines, avicularia, and dietellae may be present. Key To GENERA OF HINCKSINIDAE f.. (No avicularia, ‘no *dietellae: 66°. 06's se ere One or both ae these present. . . : 2 2. Tall pedunculate avicularia among the Snel arth Gealereaee Avicularia sessile, vicarious. 4 3. Avicularia usually paired at the Pronimal corner Eanes: strongly developed. 3 “0.0 se 605 8) 2) RY 2 eae NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 41 Avicularia not paired, or if paired they are on the lateral walls; cryptocyst less developed. . . . . wee: 4. Avicularia large, or paired on the lateral elle eels Seal but evident on the surface. . . . . Hincksina Avicularia single at distal ends of poder quicells! not evident on the surface. . . SF eAP eT ERP ray aye ns 5. Mandible very long and ieee ee ied oir pene Mandible short, pointed, not winged. . . . . . . . Elliisina Genus HINCKSINA Norman, 1903 Zooecia encrusting, entire area membranous, mural rim with or with- out spines. Ovicell endozooecial, occasionally conspicuous but usually small, short and sometimes scarcely evident. No dietellae. Avicularia usu- ally interzooecial. Genotype, Membranipora flustroides Hincks, 1880. Key To Species OF Hincksina Leaviculanian .mandible very elongate. . .. . 0.5. «.. «= 2 Mandible not extremely elongate. . . Pere era ae so 2. Mandible setiform and winged on both eee « ele op ee een Mandible not winged. Fie ee ci er Ae eS 3. With numerous spines bending over fie’ pee Pe NOS pallnda Spines wanting. . Pewee 4c Shine. ive" aque RAGE 4. Avicularia lateral and eared BaD fee ie =) aw. base a ee Avicularia not lateral and not paired. . a5 5. Mandible triangular, usually with one side fone hem the other. Be al uae gn ie velata Mandible pemtciredlen and ot ancy Bose De ee 6. Numerous spines bending foaaie over 7 the ee . . . polacantha PiGesIMMeSs) 6S GS eae ee wwe 6) des ey PRLS Hincksina alba (O’Donoghue), 1923 Plate 5, fig. 2 (Membranipora alba), O’ Donoghue, 1923 :28. Callopora alba, O’ Donoghue, 1926 :34. Encrusting, white to light yellow. Zooecia large, 0.75 to 1.08 mm long by 0.40 to 0.55 mm wide; walls high, rather thick and conspicuously elevated on the distal border; opesia oval and occupying nearly all of the frontal surface, 0.55 to 0.65 mm long; gymnocyst small; cryptocyst limited to the border of the opesia, granular and minutely crenate at its lower edge. The operculum is large, about 0.20 mm in either dimension, with a conspicuous yellow bordering sclerite. The avicularium is vicarious, taking a place in the zooecial series, and has the appearance of a symmetrical onychocellarium; it is nearly as long 42 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 as a zooecium, but much narrower, only 0.26 to 0.30 mm in width; its opesia is elliptical and partially divided near its middle, the border of the proximal portion minutely crenate. The mandible is very elongate, usually about 1 mm, the rachis slender and without denticles, strongly curved downward near the tip, the base is triangular, about 0.20 mm wide, and is hinged to the frontal surface of the chamber; the rachis is winged equally on both sides, continuing nearly to the curved tip. The ovicell is high and prominent, transverse, 0.35 to 0.40 mm wide by 0.20 mm long, endozooecial and closed by a special membrane, occa- sionally there is a small tuberosity on the top. Dietellae are present in the lateral walls and multiporous septulae in the distal wall. O’Donoghue described the species under Membranipora and changed it later to Callopora. However, the ooecia are definitely endozooecial, as shown by dissection, and the species is here transferred to the genus Hincksina. Recorded from off Protection Gap and Schooner Bay, British Columbia, down to 30 fathoms. In the Hancock collections there are several colonies on a shell labelled “local,” but without further data. Also off Santa Catalina Island, south- ern California, on a brachiopod shell. Hincksina nigrans (Hincks), 1882 Plate 5, fig. 5 Membranipora nigrans Hincks, 1882 :248. Membranipora macilenta Jullien, 1802 :25. Membranipora macilenta, Waters, 1900 :61. Callopora nigrans, Osburn, 1919 :608 ; 1923 :8 ; 1932:8. A denifera nigrans, Canu and Bassler, 1920 :102. Zoarium encrusting, coarse, light brown to nearly black. The zooecia are large, 0.70 to 1.00 mm long by 0.45 to 0.55 mm wide; distinct; mural rim raised and granulated, the distal wall arched forward and its rim somewhat elevated; opesia occupying nearly all of the front; gymnocyst vestigial; cryptocyst sometimes forming a narrow proximal shelf, but often not evident. Large multiporous septules are present, usu- ally two in the distal wall and the same in each half of the lateral wall, but more rarely some uniporous septulae are found. Small lateral avicu- laria are present on practically all of the zooecia, one on each side opposite the distal end of the operculum, the rostrum elevated and the triangular mandible directed backward. No spines. NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 43 The endozooecial ovicell is very shallow, inconspicuous and is formed by the elevation of the distal mural rim, closed by a special membrane. The position of the ooecium is rendered very conspicuous by the develop- ment of a thick-walled, bilobate ooecial cover which rises from the base of the succeeding zooecium. This structure resembles the ooecial cover in the genus Tegella, as it does not fuse with the ovicell, but it is not developed in connection with an avicularium and there is a dumb-bell- shaped membranous area on the top. The infertile zooecia do not possess this structure, but it appears on every ovicell. The center of the colony presents an altogether different appearance from the fertile area. In the infertile zooecia the operculum extends to the distal wall, but in the fer- tile ones it is somewhat remote and the frontal membrane distal to it appears to rise to close the ovicell. The M. macilenta of Jullien and Waters is merely the infertile stage of nigrans. Osburn followed Nordgaard in placing nigrans in the genus Callopora, but the endozooecial ovicell and the lack of pore chambers preclude that association. Canu and Bassler included it under their genus Adenifera, but it definitely has a small ooecium and otherwise differs from Biflustra armata Haswell, which is the genotype of Adenifera. Because of the nature of the ovicell this unusual species appears to con- form more nearly to the definition of the genus Hincksina. Hincks described the species from the Houston Stewart Channel, British Columbia. Jullien’s record of macilenta from north of Spain, and Waters’ from Wilczek Land refer to the young stage. Osburn has recorded it from Etah, Greenland; Port Burwell, Ungava, Canada, and from the Canadian Arctic Expedition Sta. 23, 70°24’N Lat., 161°25’W Long. It is doubtless another circumpolar species. Dall, Alaska collection, 1623-1670, one mature colony on a shell. It is abundant at Point Barrow, Alaska, at 18 to 25 fms, G. E. MacGinitie, collector, Alaska Research Laboratory. Hincksina pacifica new species Plate 5, fig. 1 Zoaria encrusting on shells, white to light yellow in color. Zooecia moderately large (0.55 to 0.80 mm long), distinct; opesia occupying nearly all of the front, oval or elliptical ; mural rim somewhat thickened, finely beaded, the narrow descending cryptocyst similar in texture; gym- nocyst vestigial. Operculum thin, semicircular, with yellow bordering sclerite. Avicularia vicarious, scattered, the chamber more or less rhombic in form, sides of the rostrum thin and elevated, the narrow tip often 44 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 projecting above the succeeding zooecium; mandible elongate-triangular, symmetrical, 0.30 to 0.40 mm long by 0.18 mm wide at the base, yellow with a bordering sclerite, the tip much decurved and ending in a fine point; attached by a pair of cardelles. Ovicell endozooecial, but moderately prominent, short and transverse (semilunate), the surface slightly roughened, but without an umbonate process. Dietellae present. No spines. It is apparently very similar to H. pallida (Hincks) but that species is well provided with spines, both erect and curved, and the ovicells, according to O’Donoghue (1926:31) are so immersed as to be invisible on the surface. It is also related to H. velata Hincks but in that species the avicularium is shorter and the ovicell has a different form. Type, AHF no. 14. Type locality, Albatross Station 2984 near the Guadalupe Islands off Lower California, 28°57/15’”N, 118°15’45”W, at 113 fms, two colonies. Hincksina velata (Hincks), 1881 Plate 5, figs. 3 and 4 Membranipora velata Hincks, 1881 :130. Callopora triangulata O’ Donoghue, 1926:35. The description and figure by Hincks (pl. 5, fig. 3) and that of O’Donoghue (pl. 3, fig. 28) agree in practically every detail and are correct with one exception. In spite of Hincks’ figure and the statement by O’Donoghue, the ovicell is not hyperstomial but endozooecial, as both dissection and growth stages show no mural rim beneath the aperture of the ovicell; the latter is very definitely closed by the operculum, and the cavity is formed by the forward extension of the upper part of the distal zooecial wall. The figure by Hincks shows the avicularian mandible curved while that by O’Donoghue represents it as straight, but both conditions may occur in the same colony and it is often slightly asymmetrical, one side being longer than the other. There are two very strong hinge denticles. Measurements were not given, but in our material the zooecia measure 0.60 to 0.70 mm long by 0.35 to 0.50 mm wide, and the opesia 0.40 to 0.50 mm long by 0.30 to 0.35 mm wide. The ovicell is at first transverse and arcuate, but assumes a triangular form by additional calcification. ‘The opesia occupies most of the frontal area; the walls rather thick and granulated ; gymnocyst present but often much reduced ; spines wanting, dietellae present; avicularia vicarious. No. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 45 Hincks described the species from Santa Cruz, California, and O’Donoghue lists triangulata from “Gabriola Pass; Brotchie Ledge, Victoria, B.C.” Hancock Stations: 1187-40 and 1325-41, off Santa Catalina Island, 1269-41, Anacapa Island, California; 2167, Dewey Channel off Point San Eugenio, and 2168, Cabeza Ballena, Lower California, and 431-35, off Octavia Rocks, Colombia. The known range is therefore from British Columbia to Colombia, and down to 60 fms. Hincksina pallida (Hincks), 1884 Plate 23, fig. 2 Membranipora pallida Hincks, 1884 :39. Membranipora acifera form multispinata Hincks, 1884:8. Membranipora pallida, O’ Donoghue, 1923 :25. Hincksina pallida, O’ Donoghue, 1926:31. Zoarium loosely attached by dorsal processes, thin. Zooecia elongate, elliptical, length 0.60 to 0.70 mm, width 0.25 to 0.30 mm; gymnocyst and cryptocyst vestigial; the walls thin and smooth, beset with 5 to 8 slender, pointed spines which bend somewhat over the opesia, except the most distal pair which are erect. Avicularia appear at the base of many of the zooecia, the chamber more or less quadrate, the mandible broad at the base and tapering rapidly into a very long acicular point; at first glance the avicularia appear to be mounted on the zooecial base, but their mode of development shows them to be interzooecial, and the extent of their chambers can readily be seen on the dorsal side. The mandibles average 0.35 mm in length, with a strongly decurved tip. The ooecia are endozooecial, low and inconspicuous, cucullate with a wide aperture, 0.18 mm wide by 0.10 mm long. Hincks first considered this to be a form of M. acifera MacGillivray, but later described it as a new species; his discussion and figure (pl. 19, fig. 4) are good but he did not have the ovicell and did not discuss the nature of the avicularian chamber (Virago Sound, British Columbia). O’Donoghue discovered the ovicell and removed the species to Hincksina (a number of localities in British Columbia, the San Juan Islands north- ward). Neither Hincks nor O’Donoghue mentions the peculiar mode of attachment which is by means of a short chitinous tube growing from the middle of the dorsal side of many of the zooecia. Hancock collections—a number of colonies dredged near Friday Harbor, Puget Sound, Dr. J. L. Mohr, collector. 46 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Hincksina polacantha O’Donoghue, 1926 O’Donoghue, 1926:31. Zooecium oval, elongate; margin slightly raised. As a rule there are two pairs of small erect distal spines, and on each side 10 to 13 longer spines which curve over the aperture and overlap in the midline. The aperture is completely membranous. Ooecium a marked dilatation, a little more than a hemisphere, free from ridges or perforations. Apparently it is of the separated endozooecial type. (After O’Donoghue). O’Donoghue questions somewhat the generic relationship on account of the prominence of the ooecium and it may be that the species should be referred to Callopora. It is reported only from Snake Island, British Columbia, and did not appear in the Hancock dredgings. Hincksina minuscula (Hincks), 1884 Membranipora minuscula Hincks, 1884:11. Hincksina minuscula, O'Donoghue, 1926 :30. Zooecia small, oval; margin a good deal raised, thin, smooth, no spines; on an oblong area, placed above the cell, occasionally a small circular avicularium, slightly raised, the mandible directed upward. Ooecium semicircular, shallow, just covering the extremity of the cell, smooth, with a subcircular membranous space at the back (? aviculari- um). (Condensed from Hincks.) O’Donoghue adds the information that the ‘membranous space” on the ovicell is usually occupied by an avicularium, though this structure is occasionally separated from the ooecium. Described by Hincks from Houston Stewart Channel and listed by O’Donoghue from Gabriola Pass and Bentinck Island, British Columbia. It did not appear in the Hancock dredgings. Genus APLOUSINA Canu and Bassler, 1927 The genus is characterized by the presence of endozooecial ovicells and the absence of spines, avicularia and dietellae (pore chambers). The zooecial walls are vertical and thin, with the mural rim and the very narrow cryptocyst slightly beaded. Proximally the cryptocyst usually merely rounds out the corners at the proximal end, but in narrower zooecia it may extend a short distance. There is a single multiporous communication pore in the distal wall and two or three in the lateral wall. Jullien figured 4. (Membranipora) filum with a pair of vestigial no. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 47 spines but these are usually wanting. The characters therefore are those of a simple membranipore except for the endozooccial ovicell. Genotype, A plousina gigantea Canu and Bassler, 1927. Aplousina filum (Jullien), 1903 Plate 4, fig. 1 Membranipora filum Jullien, 1903 :41 Biflustra lacroixii, Smitt, 1873 :18. A plousina filum, Canu and Bassler, 1930:5 (synonymy). Zoarium encrusting shells. The zooecia are distinct, rounded, ovate or elliptical ; varying greatly in their dimensions, ranging in lengths from 0.60 to 0.80 mm and in width from 0.40 to 0.55 mm, shorter zooecia usually being wider. The walls are thin, the cryptocyst usually a mere granulated border but sometimes a little broader proximally; gymnocyst small or wanting; the opesia occupying nearly all of the front. A minute pointed spine is rarely present on the mural rim at each side of the operculum. No avicularia. The ovicell is endozooecial but prominent, lunate, the aperture wide and closed by a special membrane; about 0.25 mm wide by 0.14 mm long, very finely granulated. Known from the eastern Atlantic region, from the Gulf of Mexico (Biflustra lacroixii, Smitt, non Audouin), and from the Galapagos Is- lands, Albatross Sta. D. 2813 (Canu and Bassler). Hancock Stations: 557-36, Isla Partida and 267, San Esteban Is- land, Gulf of California; 328, Cocos Island, Costa Rica; 431-35, Oc- tavia Rocks, Colombia; 155-34, Albemarle Island and 788-38, Daphne Major Island, Galapagos; 14 to 60 fms. Aplousina major new species Plate 4, fig. 2 The zoarium forms a thin yellowish or brownish crust on shells. Zo- oecia very large, averaging in length about 0.90 mm (range 0.80 to 1.20 mm) and in width about 0.70 mm. There is great variation in the shape, as wide as long to twice as long as wide. A narrow brown line separates the mural rims which are thin and beaded all around the border except that the distal rim is sometimes smooth. The opesia occupies all of the front ; gymnocyst wanting; cryptocyst narrow, descending sharply, often scarcely evident. The chitinous ectocyst is unusually thick, yellow to brownish in color; the operculum very large (0.25 mm wide), thicker 48 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 and browner toward the border, and the border of the aperture is also thick and brown. Dietellae present. No spines, no avicularia. The ovicell is inconspicuous, transverse, very shallow, smooth or be- coming roughened, or with a small median callosity. This species resembles 4. gigantea Canu and Bassler (1928:20) from the Gulf of Mexico, but it is even larger and the operculum is much larger (0.20 mm wide in gigantea). It is still larger than in 4. filum, the other species from the Pacific coast. Type, AHF no. 15. Type Locality, Hancock Station 1271-41, off Anacapa Island, south- ern California, 33°59’50”N, 119°24’30”W, 26 fms. Also Stations 1284- 41, Santa Rosa Island, and 1190-40, Anacapa Island, southern Cali- fornia; 275-34, Tenacatita Bay, Mexico, and 810-38, Barrington Island, Galapagos, 15 to 48 fms. The type colony from Anacapa Island, southern California, measured about 50 mm across, practically covering a dead shell. Genus CRANOSINA Canu and Bassler, 1933 The ovicell is endzooecial. A setiform transverse avicularium sur- mounts each zooecium. The dietellae are extremely conspicuous and about four in the distal half of the lateral wall, their openings to the zooecia often large. Genotype, Membranipora coronata Hincks, 1881 (after Canu and Bassler). The genus is here referred to the Family Hincksinidae with endo- zooecial ovicells. Cranosina colombiana new species Plate 4, fig. 3 Zoarium encrusting on shell, thin and white. Zooecia elongate ovoid, varying considerably in form and size, average length 0.55 mm (0.50 to 0.65), width 0.30 mm (0.25 to 0.40); separated by narrow grooves; mural rim thin, beaded in advanced calcification, slightly more elevated distally ; gymnocyst and cryptocyst usually vestigial. There are 4 or 5 weak spines on each side, somewhat curved over the opesia, but no distal spines. At the distal end of each zooecium (occasionally wanting) and oc- cupying a position in the zooecial series, is an avicularian chamber, usu- ally more or less square and measuring about 0.15 mm in each dimension, though there is much variation in the size. The avicularium is trans- verse, the mandible decurved strongly (sometimes slightly curved side- NO.1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 49 ways also), triangular at its base and much narrowed beyond, never longer than the breadth of the opesia and not winged; the mandible is attached by prominent hinge teeth. There is no external indication of ovicells except a slight elevation and thickening of the distal rim. The dietellae are large and open widely. Spines are not known in the other species which have been assigned to this genus, but the nature of the avicularium and the endozooecial ovicells seem to place the present species in Cranosina without question. It resembles C. coronata (Hincks) in general appearance, but in coronata the mandible is very elongate (nearly as long as the zooecia) and winged, and there are no spines. It also resembles Copidozoum transversum Silen (1941 :41), which may have to be placed in Cranosina, but it is evidently a different species. Type, AHF no. 16. Type locality, Hancock Station 431-35, off Octavia Rocks, Colombia, 6°47/20"N, 77°41/40”W, at 45 fms, several colonies on pebbles. Genus ELLISINA Norman, 1903 Ellisina Norman, 1903: 596. Ellisinidra Canu and Bassler, 1933 :18. Ellisina, Hastings, 1945 :87. Genotype, Membranipora levata Hincks, 1882 :249. “Zooecia mem- braniporine, ovicells endozooecial and closed by the zooecial operculum, avicularia vicarious and pointed, pore chambers present. It appears that the ovicell may be immersed in a kenozooecium (£. levata), a vicarious avicularium (£. antarctica) or an autozooecium (EF. incrustans)” (Hast- ings, 1945 :87). The above description may now stand for this genus, which has been much misunderstood even by its original author. Norman erected the generic name, giving Jevata Hincks from the Queen Charlotte Islands as the genotype, but unfortunately drew his description from a Gulf of St. Lawrence specimen which was misidentified and which belongs else- where. Norman’s description of the genus is therefore in error, but his selection of Jevata as the type definitely attaches the name Ellisina to the species /evata. Hastings (1930:713) pointed out Norman’s error in identification, but wrongly accepted his description as fixing the generic name to the St. Lawrence specimen. More recently Hastings (1945 :87) has corrected her error because “a genotype explicitly named in the intro- duction of a genus must stand despite any such discrepancies in the defi- 50 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 nition.” In the meantime Canu and Bassler (1933:18) mistakenly re- named the genus Ellisinidra with levata Hincks as the genotype. These authors apparently did not examine material of /evata since they indicate that the ‘‘ovicell is hyperstomial.” The avicularia are definitely members of a zooecial series, each one arising at the distal end of the preceding zooecium. This is clearly shown at the margin of the zoarium where a complete zooecium is followed by a developing avicularian chamber. Avicularia are usually present distal to the zooecia but they are sometimes absent and the latter condition seems to negate the supposition of Canu and Bassler that ‘‘they are neces- sary in the opening of the opercular valve.” Ellisina levata (Hincks), 1882 Plate 4, fig. 4 Membranipora levata Hincks, 1882 :249; 1884:10. Ellisinidra levata, Canu and Bassler, 1933 :18. Ellisina levata, Hastings, 1945 :87. Zoarium encrusting, smooth, white. Zooecia of moderate size (length 0.40 to 0.53 mm and width 0.25 to 0.30 mm), very distinct with broad separating grooves. Gymnocyst small and smooth, cryptocyst narrow, thin and slightly granulated. Opesia oval or elliptical, occupying nearly all of the frontal area, the walls thin and the mural rim smooth, no spines. Pore chambers present. The avicularia are interzooecial, the chambers go down to the level of the dorsal side and each chamber has a large distal pore connecting with the next distal zooecium. The chamber is more or less square (0.10 to 0.13 mm in either dimension), the aviculari- um mounted near the middle of the frontal surface, the rostrum elevated and the triangular mandible directed transversely (with some variation). According to Hastings, who has examined the type material, the ovi- cell is endozooecial and embedded in a kenozooecium (avicularian cham- ber without an avicularium), and is closed by the zooecial operculum. While this species has been the subject of so much discussion, it ap- parently has been known only from Hincks’ material, “‘Houston Stewart Channel, 15-20 fathoms ; Cumshewa; very abundant,” British Columbia. Hancock Station 1064, off Santa Barbara Island, California, 27 fms, one colony on a shell, not in reproduction. NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 51 Genus ANTROPORA Norman, 1903 Antropora Norman, 1903 :87. Membrendoecium Canu and Bassler, 1917:17. Dacryonella Canu and Bassler, 1917 :28. Antropora, Harmer, 1926 :232. Canua Davis, 1934:215. Antropora, Marcus, 1937 :50. Antropora, Silen, 1941 :43. Norman indicated the heavy cryptocyst, surrounding the aperture; the paired avicularia at the distal ends of the zooecia; the presence of dietellae, and the genotype, Membranipora granulifera Hincks. Harmer’s description is more complete, adding the fact that the ovicells are endo- zooecial and vestigial and that the avicularia do not always face each other. However, he refers to the avicularia as ‘“‘adventitious” which is incorrect since dissection proves them to be interzooecial. I am unable to draw any line of distinction between Antropora, Mem- brendoecium and Dacryonella, and Canua is merely a new name for Membrendoecium which was improperly founded and which Canu and Bassler have corrected. In all of these the cryptocyst is heavy, broad proximally and continued, at least narrowly, around the aperture; the ovicell is endozooecial and vestigial; all have small interzooecial avicu- laria at or near the proximal corners; all are provided with dietellae, and all are heavily calcified. Dacryonella has a large cryptocystal lamina, but not larger than it often is in some species that have been allotted to Antropora and Mem- brendoecium, and it has the same form. The avicularia of Antropora are not “adventitious,” as stated by Norman and Harmer, since both dissec- tion and the manner of development at the growing edge prove them to be interzooecial in origin. Antropora granulifera (Hincks), the genotype, occasionally has larger interzooecial avicularia, and this is also true of other species, such as A. (Crassimarginatella) tincta (Hastings), 4. (Membrendoecium) claustracrassa (Canu and Bassler), 4. (Membrendoecium) compressa (Osburn) and 4. (Crassimarginatella) leucocypha (Marcus). None of the above species have the hyperstomial ovicell and the type of avicu- larium with a complete hinge bar of Crassimarginatella crassimarginata (Hincks). Through the kindness of Dr. R. S. Bassler, who has shown similar courtesies on many occasions, the writer has had the opportunity to make 52 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 dissections of both fossil and recent types of Dacryonella (D. octonaria Canu and Bassler, D. tyfica Canu and Bassler and D. trapezoides Canu and Bassler), all of which show the fundamental characters of Antro- pora. Marcus (1937:50) placed Dacryonella minor (Hincks) under Membrendoecium; Osburn (1940:358) placed Dacryonello typica Canu and Bassler in Canua (Membrendoecium), and Silen (1941:43) comes to the conclusion that Membrendoecium ‘‘cannot be kept apart from Antropora.” KEY TO THE SPECIES OF Antropora 1. Avicularium with a triangular mandible. . . . Ri Be Avicularium with a semicircular or very slightly triangular! mandible, small but varying greatly in size, not regularly oriented, usually minute and vestigial. . . ; . tincta 2. Avicularia with a triangular mandible, usually paired ant di- rected forward, frequently vestigial and often wanting on one or both sides. SHANG . . Claustracrassa Avicularia with acute Gaaneular mandible, usually paired and directed toward each other across the proximal end of the zooecium, occasionally vestigial or wanting. . . . granulifera Antropora granulifera (Hincks), 1880 Plate 4, fig. 5 Membranipora granulifera Hincks, 1880a:72. Antropora granulifera, Norman, 1903 :87. Antropora granulifera, Harmer, 1926 :232. Antropora granulifera, Hastings, 1930:714. Zoarium encrusting. Zooecia variable in size, but usually from 0.35 to 0.40 mm long by 0.25 to 0.30 wide; outlined by a thin mural rim; walls heavily calcified. Gymnocyst vestigial ; cryptocyst thick and coarsely granulated, extending for about half the length of the zooecium and con- tinued around the aperture; opesia subtriangular, its proximal border straight or slightly arched, the sides contracted slightly opposite the opercular attachment. The small avicularia vary somewhat, but char- acteristically there is a pair immediately distal to each zooecium, the mandibles sharply triangular, the rostra slightly elevated and directed toward each other, their points frequently touching. Norman (p. 88) describes them as “‘in the extreme upper part of the zooecium.” Harmer (p. 233) considers them to be ‘“‘proximal avicularia belonging to the suc- ceeding zooecium.” However, they do not “belong” to either zooecium, and dissection and development at the growing edge both show them extending to the dorsal wall, and at the edge the young avicularian NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 53 chamber can be seen to develop separately before the zooecium distal to it is calcified. They are therefore definitely interzooecial in origin, what- ever their later surface relations may appear to be. They are not always paired, especially near the center of the zoarium, nor are they always directed toward each other. The ooecia are vestigial, represented by a small transverse rib between the avicularia. Dietellae are present. Probably distributed around the world in warmer waters; Madeira and Cape Verde Islands; Indian Ocean; Ceylon; Japan; East Indies at various localities; and recorded by Hastings from Jicaron Island, Pana- ma. It has not been noted on the Atlantic coast of the Americas. Hancock Station 264, south of White Friars Islands, off Petatlan Bay, Mexico, 25 fms, on a shell, and 457-35, Secas Islands, Panama, 12 fms, on shells ; also, Gulf of Panama, Galtsoff collection, on pearl oysters. Antropora claustracrassa (Canu and Bassler), 1930 Plate 4, fig. 6 Membrendoecium claustracrassum Canu and Bassler, 1930 :7. The zoarium encrusts shells, corals and coralline nodules, multi- laminar, white and glistening. The zooecia are of moderate size, about 0.40 to 0.50 mm long, but there is much variation; distinct with deep furrows; mural rim thin; cryptocyst granular, broad proximally and ex- tending on the sides along the operculum, crenulated on the inner margin. Opesia oval, the distal end narrower. At the proximal end there is, on one or both sides, a small interzooecial avicularium with a triangular mandible which is usually directed straight forward. From their position the avicularia often appear to be frontal, especially when only one is present, but disssection shows the minute cavity of the chamber extending to the level of the dorsal side. The ovicell is small, endozooecial and scarcely noticeable, but the operculum of the fertile zooecium is considerably larger and more heavily chitinized. Small dietellae are present. There are no spines, but occasion- ally small nodules occur in place of avicularia. The ancestrula is only about half as large as the later zooecia, but the “false ancestrulae” of the secondary lamina are noticeably larger than the ordinary zooecia. Canu and Bassler described the species from the Galapagos Islands. The present work shows it to be a common species, ranging from Guay- mas, Mexico, 27°56’N Lat. to La Libertad, Ecuador and the Galapagos Islands. 54 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Hancock Stations: 143-34, Wenman, 155-34, Albemarle, and 170-34, Chatham Islands, Galapagos; 212-34, La Plata, and 12-33, La Libertad, Ecuador; 411-35, Gorgona Island, Colombia; 298-34, Clarion Island, west of Mexico; 276-34, Tenacatita Bay, Mexico; 283-34 and 286-34, Thurloe Head, west cost of Lower California; 591-36, Puerto Escon- dido, 659-37, Agua Verde Bay, and 1088, Ensenada de San Francisco, Gulf of California; from shore to more than 100 fms. Antropora tincta (Hastings), 1930 Plate 4, fig. 7; plate 29, figs. 7 and 8 Crassimar ginatella tincta Hastings, 1930:708. Membranipora lacroixii Robertson, 1908 :261, (in part). The zoarium encrusts shells especially and on dead gastropod shells inhabited by hermit crabs it sometimes develops erect irregular branches as much as 50 mm in height; multilaminar to a high degree; color rang- ing from white in younger stages through light pink to pinkish-brown. The zooecia are irregularly oval, with one or two triangular or some- what rounded areas at the proximal end of each zooecium (vestigial avicularia), the appearance being similar to that of Conopeum (lacroixit) reticulum. ‘The areas, however, are not developed on the gymnocyst, as dissection shows a tube descending to the dorsal side. Small functional interzooecial avicularia are scattered irregularly among the zooecia in a similar position, or replacing a zooecium at the beginning of a series; they are often wanting over large areas, or there may be several of them in the field of the microscope at once. There are no spines and the ovi- cells are endozooecial. The mural rim is thin, but the rather heavy de- scending cryptocyst is granular and there may be a narrow horizontal shelf which sometimes develops minute denticles on its margin. The avicularian mandible is semicircular or somewhat triangular in form with a rounded tip; there is no pivotal bar, but well-marked hinge denticles are present. Because of the endozooecial ovicell this species cannot re- main in Crassimarginatella, and it has the appearance of a species of Antropora with somewhat larger and less pointed avicularia. Described by Hastings from Balboa, Canal Zone, from the Galapagos Islands, and also recorded from Mazatlan, Mexico, in the Busk collection. Hancock Stations: Occurring in 47 of the Hancock dredging stations from Point Conception, California, to Peru and the Galapagos Islands, at depths from 2 to 78 fms. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 55 Genus CAULORAMPHUS Norman, 1903 The frontal area entirely membranous, the walls comparatively thick with numerous spines; avicularia stalked, tall and slender with a narrow base, situated among the lateral spines but arising just outside of the row of spines on the lateral area of the wall. Pore chambers present. Ovicell endozooecial or wanting. Genotype, Flustra spiniferum Johnston. Key To SpEcIEs OF Cauloramphus 1. Zooecia well separated by deep grooves. . . bl Pa ae 522 Zooecia closely set, interzooecial grooves inconspicuaus. . Spiniferum 2. Moderately large, walls high, spines all long and nearly erect, avicularium tall and cradualle anla-e=1-ghove the narrow cymbaeformis af over the opesia, Seen easy eR PANGEUs gece PS 3. The two distal pairs of spines stout and erected, the others sharp- pointed and curved strongly over the opesia, usually brown in color. . : . . brunea The distal pair of panes divected few acl the Gfhers: more or less curved over the opesia, all the spines slender. . . echinus Cauloramphus spiniferum (Johnston), 1832 Plate 5, fig. 9 ?Membranipora variegata Hincks, 1889 :8. Membranipora spinifera, Robertson, 1900 :324; 1908 :265. Membranipora spinifera, O’ Donoghue, 1923 :26; 1926:39. Cauloramphus spiniferum, Hastings, 1930:713. It is a moderately large species, the colonies often covering several square centimeters. The zooecia are large, the opesia measuring 0.40 to 0.55 mm in length. The stalked avicularia are usually abundant, erect and at first glance may be mistaken for stout spines. The distal spines around the opercular area are more or less erect, those around the proxi- mal half of the opesia are smaller, sharp pointed and curve over the opesia; the usual complement of spines is 4 or 6 oral and the same number of the more proximal spines. This well-known North Atlantic species is distributed abundantly along the west coast of North America from Alaska (Robertson) to southern California, and thence more sparingly to the Galapagos (Hast- ings) and Chile. In the Hancock collections it was found at 25 stations, chiefly about the Channel Islands off the coast of southern California. Also found 56 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 abundant on rocks along shore in the region of Monterey Bay and at La Jolla, California. Also, Gulf of Panama, Galtsoff collection on pearl oysters. Cauloramphus echinus (Hincks), 1882 Plate 5, fig. 8 Membranipora echinus Hincks, 1882 :250; 1884:8. Cauloramphus echinus, O’Donoghue, 1926 :39. Resembling C. spiniferum (Johnston) but much smaller with shorter and more slender spines; the zooecia more separated; the avicularia are shorter, more bulbous, with shorter stalk, and the rostrum is more strong- ly hooked. The opesia measures 0.25 to 0.30 mm in length. The stalked avicularia are less numerous than in spiniferum. The full complement of spines is about 8 on each side, the terminal ones directed forward, the next two pairs more or less erected, and the remainder bending over the opesia; all of the spines are more slender than those of spiniferum. Described by Hincks from the Queen Charlotte Islands and recorded by O’Donoghue from numerous localities in the Vancouver Island re- gion, low tide to 30 fms. The above comparison is from a specimen in the author’s collection, “Virago Sound, British Columbia, Queen Charlotte Islands, 8-15 fath., G. M. Dawson,” and is no doubt from the same material as Hincks’ type. Hancock Station 1281-41, east of Santa Rosa Island, California, 23 fms. Also collected at Tomales Bay, California, R. J. Menzies, collector. Cauloramphus brunea Canu and Bassler, 1930 Plate 5, fig. 6 Cauloramphus brunea Canu and Bassler, 1930 :10. The zoaria are small, encrusting shells, pebbles and corallines. The zooecia are comparatively small, averaging 0.45 mm long by 0.35 mm wide; the separating grooves very broad so that the opesia are about as far apart as their own width. The mural rim is elevated and thick; the opesia elliptical, about 0.30 mm long by 0.15 mm wide; the descending cryptocyst granulated. A closely set row of spines surrounds the whole opesia; the distal 4 or 6 are longer and more erect, projecting somewhat forward; the remaining ones, 4 to 6 on each side, are smaller, more sharply pointed, and curve rather high over the opesia. The stalked avicularia, which are not abundant, are slender and elongate, the pedicel often longer than the expanded portion. NO. I OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 57 Canu and Bassler named this species because of the striking brown color of the spines in their specimens, but all gradations of color occur; some colonies have pale brown spines, others have the brown only at the base and others are pure white. The avicularia are always white and glistening. The species was originally described from the Galapagos Is- lands, Albatross Sta. D. 2815. Hancock Stations: 137-34, Clarion Island, west of Mexico; 155-34, Albemarle Island, 167-34 and 451, Charles Island, 182-34 and 462, James Island, Galapagos; 431-35, off Octavia Rocks, Colombia; 14 to 100 fms. Also, Gulf of Panama, Galtsoff collection, on pearl oysters. Cauloramphus cymbaeformis (Hincks), 1877 Plate 5, fig. 7 Membranipora cymbaeformis Hincks, 1877 :99 ; 1888 :217. Membranipora cymbaeformis, Osburn, 1912 :230. Callopora cymbaeformis, Osburn, 1919 :614; 1923 :8D. Cauloramphus cymbaeformis, Osburn, 1932 :9. The zoarium encrusts the stems and fronds of Bryozoa, hydroids, etc., especially on the dorsal side of Dendrobeania murrayana (Johnston). The zooecia are moderately large, up to 0.75 mm long, the walls high and the mural rims well separated. The gymnocyst is variable, sometimes one-third of the zooecial length but usually much shorter; cryptocyst narrow, smooth or faintly granular; 4 to 6 spines on each side, tall and slender (the distal ones may be 0.40 mm long), the proximal ones curved more or less over the opesia, the distal ones directed forward. The avicu- laria are tall, with a slender stalk which is graduated into the avicularian body, rising among the spines but taking their origin just outside of the row of spines. A common species on the Atlantic coast of North America from Cape Cod, Massachusetts, to Greenland. Recorded from Icy Cape, Alaska (Osburn, Canadian Arctic Expedition). Common at Point Barrow, Alaska, G. E. MacGinitie, collector, Alaska Research Laboratory. 58 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Cauloramphus variegatum (Hincks), 1884 Membranipora variegata Hincks, 1884:8. Jelly’s Catalog makes this a synonym of M. echinata d’Orbigny, pre- sumably with Hincks’ approval. It is a Cauloramphus as Hincks mentions the presence of stalked avicularia. Cauloramphus spiniferum (Johnston) is a very common species all along the coast and frequently has the bases of the spines dark colored as in Hincks’ description of variegata. It seems probable that variegata is merely a color form of spiniferum. The M. echinata (eschinata in the text) of d’Orbigny from Chile, is described and figured as having only three pairs of spines, all of which are on the distal half of the zooecium. Family Alderinidae Canu and Bassler, 1927 In establishing this family the authors state simply, ‘“We propose this new family for all the Membraniporae in which the ovicell is hyper- stomial.”’ This appears to be the only constant character in the midst of much diversity, but as it represents a type of reproduction different from other membranipores it is sufficiently definite. ‘The gymnocyst in the Alderinidae is usually small, but may cover half or more of the frontal length (Doryforella). The cryptocyst, in most cases, is confined to the descending portion, but it may expand to form a considerable proximal lamina. Spines are extremely varied both in number and form; occasionally they are wanting; usually they are simple in form, but they are sometimes branching and cervicorn. Avicularia are often present on the proximal gymnocyst, less frequently they occur on the lateral walls; in several genera they are interzooecial, or they may be wanting entirely. In the following classification the genera are separated, first, on the mode of interzooecial communication, either pore chambers or rosette plates; second, on the manner of the closure of the ovicell, by the oper- culum or by a special membrane; third, by the nature of the avicularia, interzooecial or adventitious on the zooecial front. Some of these charac- ters require close observation, but they appear to be the most funda- mental features of the family, and the techniques are not difficult to acquire. Key TO THE GENERA OF ALDERINIDAE 1. Pore chambers (dietellae) present... =. erie. Multiporous or uniporous septulae. No diceellees ae ee 2. No avicularia, no spimes: . 3. «= «| & a0 se) 6 nn an@eneee Avicularia presents (Vy eee CO 2 COL en) er NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 59 3. Avicularia interzooecial. . . a! ey gs aes Avicularia dependent, basal or interal or Pinotls 0) Ogee 4. Avicularium associated with a kenozooecium. . . . . Parellisina Avicularium normal, interzooecial. z . Copidozoum 5. Gymnocyst small, less than one-third of the ‘front, . . Callopora Gymnocyst extensive, one-half or more of front. . . Doryporella 6. Ovicell closed by the operculum. . . . . . Membraniporidra Ovicell closed by a special membrane. ‘ spa igs 7. Avicularia and spines wanting. . . . . . . . . . Mollia Avicularia and spines present. . Ad vot te 8. Avicularia interzooecial, with Pacrided or spatulate mandibles 2 fenestrae usually present between the zooecia. . . Retevirgula Avicularia dependent, basal or lateral or both. Pe a 9. Spines present, basal avicularium covers front or oaicell (except in JT. magnipora). . flee, negeila No spines; dorsal wall at Phite = Sess . . Bidenkapia Genus ALDERINA Norman, 1903 The front wall is entirely membranous, side walls crenulated; no spines, but nodular processes sometimes present; no avicularia. Dietellae present. Ovicell usually bearing a rib or depressed area. Genotype, Mem- branipora imbellis Hincks, 1880 :275. Alderina smitti new name Plate 6, fig. 2 Membranipora irregularis, Smitt, 1873 :8 (not d’Orbigny, 1839:17). A lderina irregularis, Canu and Bassler, 1928 :27. Alderina irregularis, Hastings, 1930 :708. Alderina irregularis, Osburn, 1940 :363 ; 1947 :13. It has been recognized for a long time (see Canu and Bassler, 1920: 142) that Smitt’s M. irregularis is not that of d’Orbigny and a new name should be given it. It seems proper that it should be named after the great Swedish bryozoologist who described and figured it carefully. Zoarium encrusting on stones, shells and corallines. Zooecia of mod- erate size, 0.45 to 0.55 mm long by about 0.35 mm wide; gymnocyst small, usually wanting, cryptocyst broad, descending, without horizontal lamina, continuing on the sides rather broadly to the operculum, the margin crenulated. The opesia is ovate and narrowed at the level of the operculum which has a brown bordering sclerite. Dietellae present. No spines, no avicularia. The ovicell is prominent, thick walled, not closed by the operculum, 0.26 mm wide. 60 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 In the Atlantic area the species has been recorded by Smitt, Osburn, and Canu and Bassler from the Gulf of Mexico, Florida Straits, north of Cuba and the south shore of the Caribbean Sea, and Hastings recorded it from Gorgona, Colombia, in the Pacific. Hancock Stations: 1325-41, Santa Catalina Island, California; 2167, Dewey Channel, west coast of Lower California; 591-36, Puerto Escon- dido, Gulf of California; 129-34, Socorro Island and 219, Clarion Is- land, west of Mexico; 155-34, Albemarle Island and 170-34, Chatham Island, Galapagos; shore to 60 fms. Also, Galtsoff collection, Gulf of Panama, on pearl oysters. The known distribution on the Pacific coast is from southern California to the Galapagos Islands. Alderina brevispina (O’Donoghue), 1926 Plate 6, fig. 3 Callopora brevispina O’ Donoghue, 1926:35. Membranipora lacroixii var. triangulata, O’ Donoghue, 1923 :25, part. This species very definitely belongs in the genus A/derina. It might readily be mistaken for the more southern A. smitti (A. irregularis, Smitt, non d’Orbigny) but for its much larger dimensions. It has the same zooecial and opesial form, the cryptocyst is of the same type and the operculum is a counterpart of that of smitti except for size. Dietellae present. A minute spine, sometimes reduced to a tiny nodule and usually entirely wanting, on each side opposite the operculum. Zooecial length 0.65 to 0.80 mm, width 0.50 to 0.60 mm. The ovicell is more transverse than that of sznitti, less rounded on the distal side and it is much broader, 0.40 mm. Known only from British Columbia waters, Gabriola Pass and Banks Island. A specimen from Cadboro Bay, Victoria, British Columbia, in the writer’s possession, extends the range slightly southward. Genus MOLLIA Lamouroux, 1916 Zooecia more or less separated and connected by lateral and proximal tubes ; cryptocyst extensive ; operculum attached to strong condyles; short dorsal tubes for attachment to the substratum; no avicularia, no spines. Ovicell hyperstomial. Genotype, Eschara patellaria Moll, 1803:75. The position of this genus in the classification has always been ques- tionable. Lamouroux (1816:115) removed patellaria from the old Lin- naean genus Eschara where Moll had described it and placed it next to Flustra. Heller (1867:94) redescribed it as a new species, Diachoris simplex, placing it in that genus because of the connecting tubules. Smitt No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 61 (1873:12) retained the genus Mollia and placed it next to Membrani- porella. Waters (1897:667) discarded Mollia and listed patellaria under Membranipora, which appears to be the best guess to date. Canu and Bassler (1928 :69), because of the appearance of the frontal associated it tentatively with the Division Coilostega, in the family Aspidostomatidae. The simplicity of M. patellaria, which lacks most of the characters commonly used in classification, is responsible for most of the difficulty. However, the absence of characters which would relate this form to any of the Coilostegan species is important, for there is no polypide tube and I have been unable to find any trace of opesiular muscles or of their dorsal attachments and there are no opesiular notches or slits. Canu and Bassler recognized this difficulty in their statement “the genus could just as well be classed next to Amphiblestrum.” It is similar to Rete- virgula in the tubular connections between the zooecia and in the tubular dorsal attachment processes but that genus possesses avicularia and spines. Because of the hyperstomial ovicell, the general membraniporoid sim- plicity and the absence of characters which would definitely locate it elsewhere, I suggest that its proper place is somewhere in the family Alderinidae and probably near to Alderina, with which it agrees in the hyperstomial ovicell and the absence of avicularia and spines. It agrees with Alderina also in the presence of pore chambers, which appear to replace the connecting tubules when the latter are absent. Mollia patellaria (Moll), 1803 Plate 4, figs. 8 and 9; Plate 29, fig. 6 Eschara patellaria Moll, 1803 :75. Diachoris simplex Heller, 1867 :94. Mollia patellaria, Smitt, 1873 :12. Membranipora patellaria, Waters, 1898 :667. Membranipora patellaria, Calvet, 1902 :12. Mollia patellaria, Canu and Bassler, 1928 :69. Zoarium encrusting loosely, attached by tubular dorsal processes, pale and shining. Zooecia small, averaging about 0.40 mm long by 0.26 mm wide, ovate with the distal end evenly rounded and slightly raised. The earlier zooecia near the center of the colony are more or less disjunct and connected by 6 or 8 short tubules, one at each end and 2 or 3 on each side; outside of the central area the side walls of the zooecia are in direct contact. The mural rim is moderately thick and coarsely granu- lated, somewhat thinner at the distal end. The cryptocyst covers about two-thirds of the frontal length, distinctly granular, its distal end more 62 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 or less transverse; the opesia is trifoliate, the operculum very small (0.08 mm wide), semicircular and attached to conspicuous cardelles. Avicu- laria and spines wanting. The species is known from the Mediterranean Sea, the Gulf of Mexi- co and Australia. Hancock Station 1662-48, Santa Cruz Island, southern California, 23 fms, several colonies on shells. Also one colony on a shell from San Felipe, Mexico. Genus MEMBRANIPORIDRA Canu and Bassler, 1917 “The operculum always closes the ovicell. No dietellae. No avicularia. One large distal septula; two pairs of lateral septulae’” (C. and B.). Genotype, M. porrecta Canu and Bassler, 1917. The ovicell is hyperstomial but is deeply excavated in the base of the distal zooecium, seeming to extend almost to the dorsal wall. The genus appears much like Alderina, with which it may readily be confused, but there are no dietellae and the ovicell is closed by the operculum. Membraniporidra porosa new species Plate 6, fig. 1 Zoarium forming a thin incrustation on a gastropod shell. Zooecia large, 0.75 to 0.90 mm long by 0.55 to 0.65 mm wide; very distinct, the walls sloping strongly inward and upward, and separated by a broad and deep sulcus; the mural rim and small gymnocyst smooth and shining; cryptocyst slightly granulated (scarcely evident). The mural rim is thin, without spines (one zooecium bears a pair of small tubercles opposite the distal end of the operculum; these are on the outside of the mural rim and do not rise above its level). The opesia is large, length 0.65 to 0.80 mm, width 0.45 to 0.55 mm, rather regularly elliptical in form. The frontal ectocyst is moderately thick and pale yellow in color; the operculum more heavily chitinized and with a thickened brown border, width 0.20 mm. No avicularia. No dietellae. The ovicell is hyperstomial, closed by the operculum, prominent, sub- globular, thick-walled, smooth and shining and perforated by numerous pores ; width 0.30 to 0.35 mm, length 0.25 to 0.30 mm. This species is placed in the genus Membraniporidra because of the absence of avicularia and spines and the presence of a hyperstomial ooeci- um closed by the operculum. The general appearance of the zooecia is similar to that of species of Aplousina, but the well-developed hyper- stomial ooecium excludes it from that genus. The perforation of the NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 63 ooecium is an unusual character in Alderinidae. The genus is well repre- sented in the American Tertiary, but no recent species has hitherto been recorded from American waters. Type, AHF no. 17. Type locality, Hancock Station 1914-39, off Pyramid Cove, San Clemente Island, California, 78-110 fms, encrusting a gastropod shell. Genus CALLOPORA Gray, 1848 Genotype, Flustra lineata Linnaeus. Gray’s genus was neglected almost entirely for many years until re- established by Norman (1903:588). The characters given by Norman are: front wall entirely membranous, marginal walls more or less thick- ened and crowned with a few or many spines. Ovicell commonly with a rib across the front. Sessile avicularia with acute mandible at the bot- tom of the zooecium and above the ovicell or in a lateral position on one or both sides of the oral opening, or in both positions in the same species. Usually two pairs of lateral and one distal dietellae. Canu and Bassler (1920:146) included the tenuirostris group of Waters, but Harmer has established the genus Cofidozoum for this group and his judgment is accepted here. This excludes those species in which the avicularia are large, vicarious and replace zooecia in the series. Callopora has been much misunderstood and many species have been listed under this genus which properly belong elsewhere. Key To Spectres OF Callopora 1. Avicularia wanting, accessory distal spines outside of the main row. Rt ee) f, ces te sl ve CONMECLIIERE Avicularia present we. eee ie Lg ee a ee 2. Lateral (distal) aviculatia only. Pk (SS Proximal avicularia present. . . Ree Vos, | 35: 3. Avicularia minute, marginal, spines long ane numerous. ; . corniculifera Avicularia somewhat larger, eniaes fewer and shorter. eee aes 4, Proximal avicularia only, single or paired. . . . - - - .~ S Both proximal and lateral avicularia present. . . . .... 9 5. Avicularia large, often curved around the opesia. . . . . . 6 Avicularia smaller, mandible straight. . . . . .-.... 7 6. Zooecia well separated, with areolations between. . circumclathrata Zooecia closer together, no interzooecial areolations. . . horrida 7. Spines 1 to 3, ovicell with a v-shaped area. . . . . . . aurita SMinesWHUIerOMS I =) Shs) 8 ee les Ose nel) ee 64 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 8. Spines usually 7 on each side, distal ones erect, proximal ones di- rected somewhat forward, meeting over opesia. . . . craticula Spines 5 or 6 on each side, directed more laterally and not meet- ing over the opesia. . . . . lineata 9, Lateral avicularia elevated, at the ede of be averculanm . armata Lateral avicularia proximal to the operculum, little elevated ; owicell-very small. os sw ee eos ce ls eee Callopora armata O’Donoghue, 1926 Plate 6, fig. 10 Callopora armata O'Donoghue, 1926 :34. The zoarium is moderately thin, encrusting and white. Zooecia dis- tinct, with occasional small interzooecial fenestrae; moderate in size (0.50 to 0.60 mm long by 0.26 to 0.30 mm wide) ; the opesia elliptical (0.35 to 0.40 mm long by 0.30 to 0.26 mm wide), constricted rather sharply at the operculum which is 0.13 to 0.15 mm in width. The walls are moderately thick, the mural rim low and smooth; the descending cryptocyst thin but conspicuously and evenly crenate to the region of the operculum ; gymnocyst occupying about one-fourth of the frontal length. Spines: a small erect one at each distal corner, along each side 4 or 5 more or less arched over the opesia, and a similar median proximal spine. Avicularia: one of moderate size on the front of the gymnocyst, often replaced by a pair of smaller ones; one on each side near the distal corners with the mandible directed forward and inward; occasionally an addi- tional small avicularium on one or both sides at about the middle of the opesia. Ovicell hyperstomial, somewhat immersed, the ectooecial layer not quite complete, slightly granular and without transverse rib; the avicu- larium distal to the ovicell is only slightly enlarged. This description differs somewhat from that of O’Donoghue, especi- ally in the number and arrangement of the avicularia, but as he found no ooecia he was doubtless describing a younger stage. Some doubt is therefore attached to the present identification. The species was described from a single specimen from Bull Passage, British Columbia in 30-35 fms. The general appearance of this species is similar to that of Tegella arctica (d’Orbigny), but it differs in the possession of pore chambers and in the nature of the ooecial cover. Off Cadboro Bay, British Columbia, several colonies collected by G. E. MacGinitie. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 65 Callopora aurita (Hincks), 1877 Plate 7, fig. 2 Membranipora aurita Hincks, 1877 :213. Membranipora aurita, Osburn, 1912 :230; 1933:21. Zoarium encrusting, usually on shells, forming very regular rounded colonies when not crowded. Zooecia moderate in size, ovate, considerably narrowed toward the distal end; walls high and strongly calcified; in older stages the cryptocyst forms a narrow shelf; gymnocyst occupying about one-fourth of the zooecial length. Usually with a single erect spine just proximal to the operculum on one or both sides, occasionally an additional smaller spine is present. Avicularia: when an ovicell is present there is a pair of small avicularia on the gymnocyst, directed forward and outward; in the absence of an ovicell there is a single larger avicularium with its mandible directed backward. The ovicell is rounded, more or less immersed, with a strong raised rib which encloses a triangular area above the orifice and which may rise to form an umbo on the top. This is a common species on both sides of the North Atlantic but its presence in the Pacific has not hitherto been noted. Canoe Bay, Alaska, 125 fms, U. S. Alaska Crab Investigation, Sta. 24-40. Also at Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector. Callopora circumclathrata (Hincks), 1881 Plate 8, fig. 2 Membranipora circumclathrata Hincks, 1881 :131. Membranipora circumclathrata, Robertson, 1908 :259. Membranipora circumclathrata, O’ Donoghue, 1923 :24. Callopora circumclathrata, O’Donoghue, 1926:33. Callopora circumclathrata, Canu and Bassler, 1923 :43. Retevirgula circumclathrata, Brown, 1948 :110. Zoarium encrusting on shells, stones and algae, but loosely attached. Zooecia about 0.50 mm long by 0.30 mm wide, well separated by deep grooves, or disjunct and united by short tubules with small fenestrae between them; walls moderately thick; mural rim smooth or slightly granular, the descending cryptocyst somewhat crenulate on its inner border; gymnocyst well developed, frequently covering one-third of the zooecial front; opesia oval to elliptical. Spines: one or two distal pairs more or less erect; three to five on each side, much flattened and bending strongly across the opesia, their points often touching. 66 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 A small avicularium, with some areolations about the base of the chamber, situated on the gymnocyst just proximal to the opesia, the mandible usually triangular but occasionally rounded; in the presence of an ovicell the avicularium becomes much larger, elongated and its chamber unites with the distal surface of the ectooecium. The ovicell is prominent, rounded, the usual transverse rib present but reduced in size and there are fine longitudinal striae on the other- wise smooth surface. The ovicell, with the distal avicularium, resembles that of the J'ege/la species. This species has recently been placed by Brown in his new genus Retevirgula, on the basis of disjunct zooecia with connecting tubules. That, however, appears to be the only character in common with that genus. Among the numerous colonies at my disposal I have found no zooeciules, though the avicularian chambers sometimes suggest that na- ture; they are very definitely frontal avicularia developed on the surface of the gymnocyst, and the tubules which appear to connect with them really are connected with the zooecium below the bases of the avicularian chambers. The ovicells of circumclathrata are not like those of Rete- virgula as they lack the fenestra in the ectooecium; they have a fairly close resemblance to those of Tegella, but the presence of large dietellae removes them from that genus. Hincks described the species from “Santa Cruz, California,” Robert- son listed it from “various localities near the coast of southern Cali- fornia,” and O’Donoghue recorded it from numerous localities in British Columbia. Hancock Station 1410-41, Santa Barbara Island, California, 20 fms. Numerous specimens from Del Monte, California, 25 feet, (in Miss Blagg’s collection) ; also in shallow water at Palos Verdes, Redondo Beach and Santa Monica, California. Pleistocene of Santa Monica Can- yon, California (Canu and Bassler). There is also a specimen labelled merely “‘off Colombia” ; the datum is probably correct as all of the other species in the lot are definitely tropical. Callopora corniculifera (Hincks), 1884 Plate 7, fig. 1 Membranipora corniculifera Hincks, 1884 :11. ?Cauloramphus triangularis Canu and Bassler, 1923 :48. Zoarium encrusting. Zooecia moderately large, 0.60 to 0.70 mm long by 0.40 to 0.50 mm wide, distinct with broad separating grooves; gymno- cyst usually small but occasionally as much as one-third of the zooecial No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 67 length ; cryptocyst narrow, sharply descending, delicately crenated. Opesia oval, narrower at the distal end. Spines all tall, especially the distal ones, usually 8 or 9 on each side but often only 5 or 6; also there are 2 or 3 smaller spines distal to the oral spines, often wanting. The avicularia are minute, sessile, on the outer side of the mural rim usually a little proximal to the operculum, with a short-triangular mandible. The ovicell is prominent, subglobose, 0.24 mm wide, and when com- pletely calcified it has a pointed umbonate process just above the aperture. (Hincks’ figure, 4a, plate 20, is misleading as the “horn-like projection from the center of the oral margin” appears to be horizontal). Canu and Bassler were aware of the similarity to corniculifera in describing their Cauloramphus triangularis from the Pleistocene of Santa Barbara, but they could not know the range of variation in corniculifera. Except for the difference in size, the characters of triangularis fall within the range of variation in corniculifera. It cannot be a Cauloramphus on account of the hyperstomial ovicell, and the “semicircular area” is similar to that of corniculifera before calcification is complete. Apparently this species has not been noted living since Hincks de- scribed it from Cumshewa, British Columbia. Hancock Station 1171-40, Catalina Island, California, 38 fms, on brachiopod shells. Also at Tomales Bay, California, 6 fms, on a clam shell. Callopora craticula (Alder), 1857 Plate 6, fig. 7 Membranipora craticula Alder, 1857 :144. Membranipora craticula, Hincks, 1880 :147. Callopora craticula, Osburn, 1923 :8D. Zoarium encrusting, forming a very spiny delicate layer on shells, stones, etc. Zooecia usually quite regularly disposed, 0.40 to 0.55 mm long by 0.25 to 0.30 mm wide; gymnocyst well developed; cryptocyst small; mural rim raised and narrow and beset with 7 to 9 spines on each side, the two anterior pairs long and erect, the others progressively shorter toward the proximal end and recumbent over the opesia; opesia oval, 0.25 to 0.30 mm long. There is a salient avicularium, with triangular mandible, on the gymnocyst in the midline or on either side; when an ovicell is present the avicularian chamber is usually enlarged and partial- ly covers the distal end of the ooecium and the mandible is enlarged. The ooecium is large, hyperstomial, not closed by the operculum, smooth, with a raised rib across the middle. 68 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 It is a common species on the coasts of Europe and the Arctic seas and Osburn has recorded it from arctic America and down the east coast as far as to Cape Cod. It does not seem to have been noted on the Pacific coast, but there are specimens in the Hancock collections from Punuk Island in the Bering Sea and Cleveland Passage, Frederick Sound, Alaska. Common at Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. Callopora exilis (Hincks), 1882 Plate 6, fig. 8 Membranipora exilis Hincks, 1882 :249. Callopora exilis, O’ Donoghue, 1926 :33. Zoarium encrusting, thin. Zooecia distinct, rather regularly elliptical ; the opesia occupies nearly all of the front and averages 0.40 mm long by 0.26 mm wide; walls low, well calcified, the descending cryptocyst nar- row and smooth on its inner border; gymnocyst often well-developed. There are two pairs of small distal erect spines, and on each side are 4 to 6 small spines which bend slightly over the opesia. Occasionally there is a small avicularium on the side of the lateral wall, just outside of the row of spines; it is so obscure that it is easily overlooked. The ooecia are small, rounded, prominent, without a rib, and smooth or with minute striations, 0.26 mm wide by 0.20 mm long. Hincks described the species from Houston Stewart Channel, Queen Charlotte Island and O’Donoghue recovered it from Banks Island, Vic- toria, British Columbia and added to Hincks’ description. Canoe Bay, Alaska, 125 fms, U. S. Alaska Crab Investigation, Sta. 24-40. Callopora lineata (Linneaus), 1758 Plate 6, figs. 4 and 5 Membranipora lineata, Hincks, 1880 :143. Callopora lineata, Osburn, 1923:7D. Callopora lineata, O’ Donoghue, 1926 :32. Zoarium encrusting. Zooecia moderate in size, averaging about 0.60 mm long by 0.35 mm wide; gymnocyst usually well-developed, occupy- ing about one-third of the length; cryptocyst moderate, granulated, with- out horizontal lamina. Opesia elliptical or a little narrowed distally; walls beset with about 7 spines on each side, the two distal ones erect, the others bending somewhat over the opesia. Avicularia elevated on the gymnocyst, usually single (sometimes a smaller pair) with triangular mandible. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 69 Ovicell prominent, rounded, smooth with a transverse rib, width about 0.25 mm. This species has some resemblance to C. craticula, but Hincks (1889: 46) has indicated the differences: M. lineata differs in the larger size, the less regular arrangement of the zooecia, the spines rounded and much less recumbent. It is a common Atlantic species, on the American coast from Cape Cod to Greenland and Osburn has recorded it as far west in the Arctic Ocean as Bernard Harbor, Northwest Territory (about 115 degrees W). O’Donoghue lists it at a number of localities in British Columbia. Hancock Station 1662-48, Santa Cruz Island, southern California. Specimens also from Dillon Beach, California, Menzies, collector, and Nunivak Island, Alaska. It does not appear to be a common species on the Pacific coast. Callopora horrida (Hincks), 1880a Plate 6, fig. 9 Membranipora horrida Hincks, 1880a:82; 1884:7. Membranipora californiensis Waters, 1898 :681. Membranipora horrida, Robertson, 1908 :260. Membranipora horrida, O’ Donoghue, 1923 :24. Callopora horrida, O’ Donoghue, 1925 :97 ; 1926:33. Zoarium encrusting shells, stones, sponges, etc. Zooecia ovate, very distinct with wide grooves; opesia more or less ovate, the mural rim thick, elevated and slightly crenate. Dietellae in the lateral and distal walls. Two or three pairs of stout erect distal spines and the same num- ber of lateral ones which are smaller, sharp-pointed and curved over the opesia. A large avicularium is located on the basal gymnocyst, its long pointed mandible, which is often curved laterally, directed forward to one side of the opesia; occasionally smaller avicularia of similar form are present in the same position. Ooecium rather small, globular, with a transverse rib near its aper- ture; the avicularium of the distal zooecium is often attached partly to the ooecium, but does not cover it as in the genus Tegella. There is much variation in the number and size of the spines and in the width of the separating grooves. Hincks described this species from California, as did Waters his cali- forniensis. Robertson listed it from Puget Sound southward to Pacific Grove, California. O’Donoghue recorded it from numerous localities, Puget Sound northward in British Columbia. 70 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Hancock Stations: 147-34, Tagus Cove, Albemarle Island, Galapa- gos, 30 fms; 788-38, Daphne Major Island, Galapagos, 70 to 80 fms; 1232-41, off San Pedro breakwater, California, 19 fms; 1410-41, Santa Rosa Island, California, 17 fms; and 275, Raza Isla, Gulf of California, 40 fms. Apparently it is much more abundant in its northern range. Callopora whiteavesi Norman, 1903 Plate 6, fig. 6 Callopora whiteavesi Norman, 1903 :589. Membranipora lineata, Smitt, 1867 (in part, Pl. 20, fig. 26). Membranipora whiteavesi, Levinsen, 1916 :443. Callopora whiteavesi, Osburn 1932:8. Zoarium encrusting. Zooecia of moderate size, 0.50 to 0.60 mm long by 0.35 to 0.40 mm wide, the oval to elliptical opesia occupying about three-fourths of the length. The zooecia are well separated by rather broad grooves; the cryptocyst granulated and without horizontal lamina, the gymnocyst smooth. The spines, 8 to 11 on each side, are long and more or less erect, the distal ones directed forward; a few smaller termi- nal spines are sometimes present beyond the distal rim. Avicularia ap- parently are entirely wanting. The ovicells are globose, prominent, smooth or delicately frosted with minute tubercles; in complete calcification there may be a slightly raised rib enclosing a triangular area on the front. Described by Norman from East Finmark, Norway; since recorded by Levinsen from Greenland, and by Osburn from Ungava, Hudson Strait, and Port Churchill, Manitoba. The present records indicate that it probably has a circumpolar distribution. Canoe Bay, Alaska, along shore, (U.S. Alaska Crab Investigation) ; Point Barrow, Alaska, 12 fms, G. E. MacGinitie, Arctic Research Lab- oratory. Callopora inconspicua (O’Donoghue), 1923 Membranipora inconspicua O’ Donoghue, 1923 :29. ‘The small zooecia are oval, tending toward polygonal. The edges are covered by a thin, almost transparent, white lamella, which passes up- ward to a fairly regular oval aperture. he opesia has a sort of curved border around it, wider at the posterior end. Commonly two small avicu- laria are borne on this border, one on each side about one-third of the way from the distal end; their rounded mandibles face upward and No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA fii slightly inward and forward; sometimes, when an ooecium is present, a third slightly larger avicularium is produced at the end of this, its mandi- ble facing upward and forward. Spines, 3 pairs of distal ones, long and erect, and back of these about 5 pairs of small pointed spines directed inward over the aperture. Ooecium small, but prominent, smooth, sub- globular. (After O’ Donoghue). This species cannot remain in Membranipora, as that genus is now understood and, while its author did not discuss all the characters of generic importance, it appears to be best allocated to Callopora. Described from Northwest Bay and off Snake Island, British Columbia. Callopora (?P) verrucosa Canu and Bassler, 1930 This is a very unusual species which has not appeared in the Hancock collections. Canu and Bassler (1930 :9) state that “The ovicell is hyper- stomial, globular,” which would indicate the genus Callopora. On the other hand, there are small interzooecial avicularia in the corners between the zooecia and some of these are vestigial, while around the zoarial border there is a band of similar heterozooecia, many of which bear avicularia with a short triangular mandible. The nature of the inter- zooecial avicularia and their vestigial counterparts suggests the genus Antropora, but the hyperstomial ovicell prevents inclusion in that genus. It was described from the Galapagos Islands, Albatross station D.2813. Genus COPIDOZOUM Harmer, 1926 “Zooecia with greatly reduced gymnocyst, the membrane covering almost the entire frontal surface. Cryptocyst most developed proximally, moderate to extensive. Spines present, absent or vestigial. Avicularia vicarious, numerous, alternating with the zooecia, the rostrum triangular proximally, usually narrow and linear distally, the mandible of corres- ponding form. Ovicells hyperstomial.” (Harmer, 1926:226). Genotype, Membranipora plana Hincks. Key To Species Copidozoum Peespines wanting. @s 2c A 6k a a tS @ Soe ee Spines present. 5) 2. Zooecia large, cryptocyst moderately developed, opesia ‘elliptical. . . planum Zooecia moderate size, cryptocyst thick and coarsely oranulated, @pesia ovale 2. . «3 + + «© « %.)o. eam eeeRONEre 3. Spines all simple. . . Pr Per Moai Distal spines forked or aleicorn. soe yO nM Pa erareeien: 72 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Copidozoum tenuirostre (Hincks), 1880a Plate 7, fig. 4 Membranipora tenuirostris Hincks, 1880a:70; 1884:7. Callopora tenuirostris, O’ Donoghue, 1926 :33. Callopora tenuirostris, Canu and Bassler, 1929 :8. Copidozoum tenuirostre, Marcus, 1937 :48. Zoarium encrusting. Zooecia of moderate size, usually between 0.45 and 0.55 mm in length, and 0.30 to 0.40 mm wide. Distinct, the walls thick and the descending cryptocyst heavy and coarsely granulated, with- out a horizontal lamina; gymnocyst little developed. Opesia ovate, usu- ally distinctly narrowed at the operculum. Dietellae are usually present, one in the distal and one or two in the lateral wall, but the pore chambers may be absent leaving only large multiporous rosette plates, which ap- pears to agree with the observations of Waters (1898 :685) on Mediter- ranean specimens. The avicularia are interzooecial, occupying the place of zooecia; the chamber usually diamond-shaped ; the rostrum long, elevated toward the tip and with a narrow groove; the mandible is elongated, almost filiform, with a triangular base attached to a pair of strong den- ticles. Spines wanting. The ovicell is prominent, globose, minutely porous and decorated with minute knobs or merely granulated; not closed by the operculum. The original description by Hincks (1880:70) states that there is ‘“‘an acuminate spine at the bottom of the aperture bending inward, and usually two or three on each side.” Spines are entirely wanting on all of the Pacific coast specimens; Waters (1898:685) found no lateral spines, except occasionally a small one proximal to the ovicell in Mediterranean material; and Marcus (1937:49) found no spines on specimens from Brazil, though they were present, as Hincks illustrated them, in speci- mens from St. Helena Island (1939:201). Distributed around the world in tropical and temperate waters. Hincks and O’Donoghue recorded it from several localities in British Columbia and Canu and Bassler from the Galapagos Islands. In the Hancock collections it occurred at 56 stations, distributed from northern California to Peru and the Galapagos Islands, and from low tide to 70 fms. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 73 Copidozoum planum (Hincks), 1880 Membranipora plana Hincks, 1880a:81. Copidozoum planum, Hastings, 1930:713. “Zooecia large, oval, distinct, surrounded by a narrow border, which is rounded and finely crenate, sometimes slightly produced below the aperture and pointed; front wall wholly membranous, very much on a level with the margin of the cell, so as to give a flattened appearance to the surface of the zoarium. Avicularia scattered, placed in somewhat lozenge-shaped intercellular spaces; beak elongate, straight, occupying the center of the area, traversed by a narrow groove which expands toward the lower extremity; mandible with an enlarged base, above it setiform, slightly curved at the top. Ooecium rounded, rather large, frosted.” (Hincks 1880a:81). The species was described from Australia and has since been recorded from the Mediterranean (Canu and Bassler 1928:32); from Japan (Membranipora vibraculoides Okada, 1923:223), and Hastings has listed it from Coiba, Panama; Gorgonia, Colombia; the Galapagos Is- lands, and also mentions specimens from California in the British Mu- seum. In all the numerous specimens I have examined from all along the coast from California to the Galapagos Islands there are none that I can positively separate from fenuirostre except on the basis of the lack of spines. I have found occasional specimens with thinner walls, but these were not larger than tenuirostre. This raises the question whether only those with heavy spines, as shown by Hincks (1880, plate 9, fig. 3) and Marcus (1937, text fig. 7) should be included in tenwirostre and those without spines under planum, regardless of the width of the cryptocyst. On this basis all of the Pacific coast specimens belong under planum. Copidozoum protectum (Hincks), 1884 Plate 7, fig. 5 Membranipora protectum Hincks, 1884:10. Membranipora protectum, O’ Donoghue, 1923 :25. Amphiblestrum protectum, O’ Donoghue, 1926:38. Zoarium encrusting. Zooecia very distinct, moderate in size, 0.40 to 0.50 mm long by 0.25 to 0.30 mm wide. Gymnocyst and cryptocyst both small and the opesia occupies nearly all of the frontal area. The mural rim is thin and high, the descending cryptocyst narrow, without hori- zontal shelf, granulated. Spines: one erect, simple or slightly bifid, at each distal corner; one on each side of the operculum, also erect and 74 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 bifid; one more proximally on each side, alcicorn with 3 to 6 points, recumbent over the opesia; in advanced stages the points may fuse, as stated by O’Donoghue. The avicularia are interzooecial, with a very elongate narrow rostum, and the mandible is similarly long (as much as 0.40 mm) and attenuated or filiform. Dietellae present. Ovicell rather large, averaging 0.20 mm wide, prominent, the surface delicately granulated. O’Donoghue placed this species “provisionally” under Amphible- strum, but the opesia occupies all of the frontal area; there is no hori- zontal cryptocyst, and the avicularia are vicarious. Described by Hincks from British Columbia and recorded by O’Dono- ghue from numerous localities from Victoria and the San Juan Islands northward. Hancock Stations: Distributed along the whole western coast of the United States and south along the peninsula of Lower California, and in the Gulf of California. Copidozoum spinatum new species Plate 7, fig. 3 The only colony completely encrusts a rounded object. The zooecia are of moderate size, 0.45 to 0.55 mm long by 0.26 to 0.30 mm wide; distinct and the mural rims never in contact; opesia elliptical ; mural rim thin and the cryptocyst very narrow and scarcely granulated. The rim is beset with numerous spines of equal size, 5 to 7 on each side. The interzooecial avicularia are small, the rostrum short (0.13 mm), but otherwise similar to those of tenuirostre. Multiporous septulae. Ovicell globular and very prominent, about 0.18 mm wide; perfor- ated with minute pores and delicately granulated. The pores are defi- nitely larger than in tenuirostre where they are usually visible only by transmitted light in balsam mounts. ‘The zooecia have much the appearance of C. (Membranipora) plan- um, as shown in Hincks’ plate 11, fig. 2 (1880), but they are much smaller and the array of marginal spines is an important difference. Apparently all of the spines are simple and of about the same size, judg- ing by the bases; the specimen was dead and only the bases of the spines remain. Type, AHF no. 18. Type locality, Hancock Station 339, Gulf of Dulce, Costa Rica, 8°24’20”"N, 83°13740”W, 48 fms. One colony. No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 75 Genus PARELLISINA Osburn, 1940 This genus was erected by Osburn (1940:360) to include those species, formerly listed under Membranipora and Callopora, in which the avicularium is always associated with a heterozooecium or kenozooeci- um. The avicularian chamber is proximal to that of the kenozooecium and separated from it by a vertical wall. Besides the genotype, Membrani- pora curvirostris Hincks, the following species seem to belong here: M. falcata MacGillivray, M. albida Hincks, Callopora tenuissima Canu and Bassler, C. subalbida Canu and Bassler, P. latirostris Osburn and Ellisina latirostris Silen (not Osburn). Parellisina curvirostris (Hincks), 1862 Plate 8, fig. 8 Membranipora curvirostris Hincks, 1862. Ellisina curvirostris, Harmer, 1926 :228. Callopora curvirostris, Canu and Bassler, 1928 :32. Ellisina curvirostris, Hastings, 1930:711. Parellisina curvirostris, Osburn, 1940 :361. Zoarium encrusting. Zooecia separated by grooves, gymnocyst small or wanting; mural rim thin, little raised; a vestigial spine on either side of the aperture, often wanting, and occasionally others on the lateral walls; a narrow granulated cryptocyst. Ovicell hyperstomial, small but prominent, globose, the frontal surface delicately granulated. The avicu- larium is interzooecial, large and more or less curved sideways; followed in series by a kenozooecium which varies considerably in size and form and which is covered by a membrane; its opesium is usually more or less triangular and a delicate mural rim may be present. Hastings recorded the species from the Galapagos Islands. Otherwise it is known around the world in warmer seas. Hancock Stations: 142-34, Clipperton Island, west of Mexico, and 147-34, 155-34, 198-34 and 362-35, all from the Galapagos Islands. Also in the Galtsoff collection on pearl oyster shells from the Gulf of Panama. Genus BIDENKAPIA new genus Zoarium encrusting and loosely attached or rising in flabellate ex- pansions or contorted frills. Zooecia large, walls very high and thin with multiporous rosette plates; dorsal wall smooth with numerous white punctations; gymnocyst and cryptocyst well developed; no spines; usu- ally a single large avicularium covers the whole breadth of the gymno- 76 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 cyst, but occasionally this may be replaced by a pair of smaller ones in the proximal corners. Ooecium prominent, hemispherical, smooth, hyper- stomial and not closed by the operculum. In the presence of the ovicell, the larger avicularium appears to be always absent, but when the smaller avicularia are present one of these is usually located at one side distally and its chamber is not involved in the ooecial cover. Genotype, Mem- branipora spitsbergensis Bidenkap, 1897. While definitely a member of the family Alderinidae, the combina- tion of characters presented by M. spitsbergensis will not permit its inclusion in any known genus. Bidenkapia spitsbergensis(Bidenkap), 1897 Plate 8, fig. 6 Membranipora spitsbergensis Bidenkap, 1897 :619. Membranipora spitsbergensis, Nordgaard, 1900 :9. Membranipora spitsbergensis, Kluge, 1906 :38. Callopora spitsbergensis, Nordgaard, 1918 :44. Callopora spitsbergensis, Osburn, 1919 :609; 1923:8D; 1932:8. ‘The zoarium is encrusting but loosely attached or rising in bilaminate or unilaminate frills or flabellate expansions, rough, conspicuous and yellow to orange in color when fresh. The zooecia vary much in dimensions but are usually large, averag- ing about 0.80 mm long by 0.45 mm wide, occasionally more than 1. mm in length, and the zooecia are unusually deep. The walls are all comparatively thin, the mural rim thin and smooth or granulated, the dorsal wall thin, smooth, shining and thickly punctate with white dots. In the absence of ovicells and avicularia the gymnocyst is usually little developed ; the cryptocyst varies greatly, sometimes filling a third of the proximal end of the opesia and again it is scarcely noticeable. Large multiporous septulae are present, about a third of the distance above the dorsal wall. Spines are entirely wanting. ‘Two sizes of avicularia are known. Usually a large one occupies the whole width of the proximal end of the zooecium, the short rostrum ele- vated and the bluntly triangular mandible directed backward or laterally ; frequently this type is wanting and they are never present when an ovi- cell is developed on the preceding zooecium. Instead of the single large avicularium there is sometimes a pair of smaller ones, one in each proxi- mal corner, and one of these is rarely present at the distolateral side of the ovicell. There is some intergradation between the two types of avicu- laria, single median ones occasionally present among the smaller avicu- NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA ded. laria, and small lateral ones rarely on colonies with the large median type, but as a rule only one type of avicularium is present in any one colony. The ovicell is prominent, hemispherical, about 0.40 mm wide, hyper- stomial, the aperture wide and covered by a special membrane; the ecto- oecial wall smooth and shining, with a slightly elevated collar around the ooecial aperture when complete. Originally known from Spitsbergen, its range has been extended (Osburn 1919, 1923) to west Greenland and Hudson Strait, and from Icy Cape, Alaska. Punuk Island, Bering Sea, 15 fms on shells. Prof. G. E. MacGinitie has recently collected it also at Point Barrow, Alaska, 18 to 25 fms, common. Bidenkapia spitsbergensis var. alaskensis new variety Plate 8, fig. 7 This variety, partially discussed above, occurs with the typical va- riety, along the coast of northwestern Alaska. Since some colonies present only the smaller avicularia, it seems advisable to give it a varietal name. The difference was first noted by Osburn (1923:8D), in a specimen from Icy Cape, Alaska (Canadian Arctic Expedition Sta. 23). “In this one small specimen the zooecia are smaller, the avicularia are smaller, and there are sometimes two of them at the distal corners of the zooecium and faced toward each other. The ooecium and the zooecial characters are similar to those of spitsbergensis and the dorsal wall is similarly perforated.” Type, AHF no. 19. A number of colonies, with those of the typical form at Point Bar- row, Alaska, 23 fms, G. E. MacGinitie, Arctic Research Laboratory. Genus TEGELLA Levinsen, 1909 “The zooecia, which have spines and a slightly developed cryptocyst, are provided with multiporous rosette plates. Hyperstomial ooecia with an incompletely calcified ectooecium, which are again surrounded by an avicularium.” (Levinsen). The most important generic character is the absence of pore chambers, which separates the species of this genus from Callopora. Levinsen’s statement concerning the ovicell is not quite clear; the ectooecium usually does not fully cover the entooecium, but it is usually heavily calcified; the avicularian chamber may cover the distal end of 78 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 the ooecium and be so completely fused with it as to appear as one struc- ture, or it may be partially separated by a groove. he gymnocyst is well developed and bears a large avicularium; small lateral avicularia on the mural rim are also present in some of the species. Flustra unicornis Fleming is the genotype. Differentiation of the species depends chiefly on the arrangement of the spines and avicularia, which are often of uncertain value but which appear to be fairly constant in this genus. This is especially true of the avicularia; lateral avicularia present or wanting; if present they may be directed forward or backward in different species. The spines are not so constant but erect tubular spines may be present or absent; other spines may curve closely over the opesia as in arctica, or stand more or less erect, and there is considerable variation in the number present. In the ovicell the transverse rib which is the proximal end of the ectooecium varies so much with calcification that its importance is doubtful, but it serves to differentiate certain species from others which lack the strong rib. Key TO THE SPECIES OF Tegella 1. Small lateral avicularia opposite the eu ep oe fe i ke No lateral avicularia. “. =: Bagi: 2. A strong, erect, tubular spine, Renal on one side only one or more pointed, curved spines, often wanting. . . . . armifera No erect tubular spines ; 2 to 4 flattened, pointed spite on each side bent low over the opesia. . . 3. Lan aretied 3. Avicularia wanting; ovicell with a large fenestra or r uncalcified area at, the tops, 0. . . magnipora Pointed avicularia on the kesa. ie mncecee more or less cover- ing the ovicell when this is present. . . 4 4. No erect tubular spines ; ; | to 3 curved spines bending over ‘the opesia, often wanting; ovicell prominent. . . . aquilirostris An erect tubular spine present on one or bothsides. . . . . . 5 5. Ovicell small, deeply immersed, avicularia large. . . robertsonae Ovicell larger and prominent, avicularia smaller. . . . wunicornis Tegella unicornis (Fleming), 1828 Plate 9, fig. 2 Flustra unicornis Fleming, 1828 :536. Membranipora unicornis, Hincks, 1884 :7. Tegella unicornis, Osburn, 1923: 8D. Zoarium encrusting. Zooecia moderately large, the opesia large and oval, slightly narrowed at the distal end; rim broad and finely crenulate, especially on its inner side; usually bearing 4 spines at the distal end, the more anterior pair small, erect and often wanting, the other pair larger, No. | OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 79 erect, one usually larger than the other. An avicularium on the proximal gymnocyst, mounted on a raised projection; when an ovicell is present the avicularium appears to arise from the ovicell. The ovicell is prominent, smooth with a transverse rib and the distal avicularian chamber forms a part of the cover. In many respects this species is so similar to T’. armifera (Hincks) that the latter was described as a variety. However, the distolateral paired avicularia of armifera are never present in unicornis and there are other slight differences. Hincks listed the species from Houston-Stewart Channel, British Co- lumbia. A common species in the northern Atlantic; on the North Ameri- can side from Greenland south to Cape Cod, Massachusetts ; in the Arctic west to the Northwest Territory, Canada. Hancock Stations: 1234, Santa Rosa Island, and 1245, Santa Cruz Island, southern California; southern Alaska; Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. Tegella armifera (Hincks), 1880 Plate 9, figs. 1 and 7 Membranipora armifera Hincks, 1880a:82. Membranipora sophiae var. armifera, Waters, 1889 :680. Callopora unicornis var. armifera, Norman, 1903 :27. Membranipora cassidata O’ Donoghue, 1923 :27. Tegella cassidata, O’ Donoghue, 1926 :36. Tegella unicornis var. armifera, Osburn, 1933 :24. This species is very similar to wnicornis Johnston, except for the pres- ence of the lateral avicularia. This difference is so constant that I believe armifera should be given specific standing. There is one other character that may be of some importance and that is the occasional presence of a curved, pointed spine which bends somewhat over the opesia and which I have never observed in wnicornis; also armifera is considerably larger. The zoarium encrusts shells, stones, algae and occasionally even small stems. The zooecia are rather large and have a wide range in measure- ment, length 0.60 to 0.80 mm, width 0.35 to 0.50 mm, and occasionally transcending these measurements in either direction; shorter zooecia are usually correspondingly wider, the ovate opesia varying with the form of the zooecium. The basal gymnocyst is well developed and bears an avicu- larium; the descending cryptocyst is somewhat thick and granulated. The spines are as follows: a small erect spine at or near each distal corner, frequently wanting; a tall stout spine on either side near the attachment 80 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 of the operculum, one of these often smaller or wanting; a pointed spine curving somewhat over the opesia at about its middle, very inconstant, usually some on the zoarium but occasionally wanting entirely. Lateral avicularia are present on one or both sides, mounted on an elevated base close to and distal to the stout spine, often wanting on one side; the triangular mandible directed proximally and somewhat vertically and outward. The ovicell is large and prominent; the ectooecial layer forming a ridge across the middle, varying greatly in the amount of calcification and in the form and amount of curvature. The median avicularium is greatly increased in size, with a long-triangular mandible which is turned somewhat sideways; the avicularian chamber united with the ectooecial layer to a greater or less extent, sometimes surmounting the ovicell and seeming to arise from it. I am unable to distinguish cassidata O’Donoghue from armifera by any constant character after direct comparison with colonies of the latter from the Atlantic coast. O’ Donoghue says of the lateral avicularia, “the mandible lies almost vertically and is directed anteriorly and slightly in- ward,” which must be a dapsus calami as his figure (pl. 2, fig. 15) clearly shows it directed proximally and outward. There is considerable varia- tion in size and elevation and in the erection of the mandible, but in all cases they are turned backward and outward as in armifera. Hincks described M. armifera from the Gulf of St. Lawrence; and Osburn listed it under M. arctica from Cape Cod, Massachusetts, and it has been reported from the arctic seas of Europe and America. O’Dono- ghue listed cassidata from numerous localities in British Columbia, “a fairly common species and a very characteristic one.” Hancock Station 1245, Gull Island off Santa Cruz, California; off San Pedro, California; Nash Harbor, Nunivak Island, Alaska, and Pun- uk Island, Bering Sea. Also common at Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. Tegella magnipora new species Plate 9, figs. 3 and 4 Zoarium encrusting, reddish brown in color. Zooecia moderately large, varying in length from 0.65 to 0.90 mm and in width from 0.35 to 0.45 mm; mural rim thin and smooth or slightly granulated ; gymno- cyst moderately developed, sometimes almost wanting ; descending crypto- cyst granulated, narrow, occasionally a little expanded laterally at the proximal corners. The opesia occupy nearly all of the frontal area, ellipti- No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 81 cal or oval in form. The frontal membrane is thick and brownish, the operculum heavily chitinized and 0.20 mm or more in breadth. The usual complement of spines is 4 on each side, very evenly spaced, stout and erect or nearly so; the second pair, opposite the operculum, are somewhat taller and much stouter than the others. No avicularia are to be found on the several colonies studied. The ovicell is of striking appearance, even for a Tegella: very promi- nent, somewhat transverse (0.30 mm wide by 0.25 mm long), thick and heavily calcified, with a thick, elevated rim on the top surrounding a large, irregularly rounded area which is covered by a membrane, and frequently the distal side of the rim rises into a point. The endooecium is smooth, thin and only slightly calcified and is not perforated, and it is not fused with the outer layer. The ectooecium is very irregular in complete calcification and the area varies in form from perfectly circular to transversely or longitudinally elliptical, or it may be more or less irregularly rounded. On the distal aspect of the ooecium there is another rounded fenestra in the position usually occupied by an avicularium in this genus, but it is covered by a smooth membrane. There are large multiporous rosette plates in the lateral and distal walls. By the definition of the genus Tegella, the ovicell is surrounded by an avicularium. In the present species there is no evidence of an avicu- larian mandible, but the distal fenestra referred to may possibly be in- terpreted as the vestige of an avicularium. In other characters the species appears to agree in all respects. Type, AHF no. 20. Type locality, Canoe Bay, Alaska, 125 fms on dead shells, several colonies. Also at Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector. Tegella robertsonae O’Donoghue, 1926 Plate 9, fig. 5 Membranipora unicornis, Robertson, 1900 :324. Membranipora occultata Robertson, 1908 :262 (not M. occultata Wat- ers). Membranipora occultata, O’ Donoghue, 1923 :25. Tegella robertsoni O’ Donoghue, 1926 :36. Zoarium encrusting shells, sponges and larger algae. Zooecia moder- ate in size, 0.55 to 0.65 mm long, distinct only in young stages. Gymno- cyst well developed, usually about one-third of the frontal length; crypto- 82 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 cyst granulated, without horizontal lamina; walls high, the rim thin when young. Opesia elliptical or oval. ‘There is an erect hollow spine on one side at the base of the operculum and frequently a smaller one on the opposite side; proximal to these on the sides are frequently 1 to 3 smaller curved spines bending somewhat over the opesia. An avicularium is usually present on every zooecium, large, about half the zooecial length, the mandible elongate triangular, its tip slightly rounded and strongly decurved, pointing forward and to one side of the opesia. The primary ovicell is small; the ectooecium forms a complete cover separated from the endooecium. The wall of the distal avicularium usu- ally fuses completely with the ectooecium. Miss Robertson first listed the species from Alaska and Queen Char- lotte Islands as M. unicornis and later described it as MM. occultata, over- looking the fact that Waters had previously applied that name to another species. O’Donoghue listed it for a number of British Columbia locali- ties, and Sakakura (1935:8) recorded it from Japan. Hancock Station 1662-48, Santa Barbara Island, California. Also from Monterey Bay, (Robertson), Dillon Beach, (Menzies), California, and Clayoquot Sound, British Columbia (E. F. Ricketts). The known range is from southern Alaska to southern California. Tegella arctica (d’Orbigny), 1851 Plate 9, fig. 6 Membranipora conferta Hincks, 1882 :249. Membranipora sophiae form matura, Hincks, 1884 :9. Callopora arctica, Osburn, 1919 :608. Zoarium encrusting on rocks and shells. Zooecia of moderate size, about 0.60 mm long; the opesia elliptical or ovate, averaging about 0.40 mm long; gymnocyst well developed; descending cryptocyst narrow and granulated; the mural rim bears on each side 2 to 4 stout flattened spines which bend down closely over the opesia, the pointed tips some- times overlapping; the absence of erect hollow spines distinguishes this species readily from others of the genus in this region, though a minute vestigial spine may occur at the base of the lateral avicularium. The mural rim also bears on each side a small elevated avicularium with a triangular mandible which is directed distally and somewhat toward the midline. A larger avicularium may be present in the usual position on the gymnocyst, but is never so much enlarged as in the other species, nor does the chamber cover the ovicell to such an extent; often they are wanting over most of the zoarium. NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 83 The ovicell is broad, not prominent, and the proximal edge of the ectooecium forms a slightly arcuate ridge across the middle. In advanced stages of calcification the ovicell tends to become immersed. Hincks recorded this species from Houston-Stewart Channel, British Columbia. It is known from the northern coasts of Europe and ranges down the east coast of North America from Greenland to Cape Cod, Massachusetts. Punuk Island, Bering Sea, and Cleveland Passage, Frederick Sound, Alaska. Also common at Point Barrow, Alaska, G. E. MacGinitie, col- lector, Arctic Research Laboratory. Tegella aquilirostris (O’Donoghue), 1923 Membranipora aquilirostris O’ Donoghue, 1926 :28. Tegella aquilirostris, O’ Donoghue, 1926 :37. Zoarium encrusting on stones, shells or kelp. Zooecia of moderate size, opesia large, oval, walls raised, smooth; gymnocyst well developed ; no erect spines, one to three pointed spines curving over the opesia. Ovi- cell prominent, with a strong transverse frontal ridge. The basal avicu- larium is large and when an ovicell is present the chamber becomes more or less united with the ectooecium. (After O’ Donoghue. ) This species appears to be rather closely related to robertsonae but the prominent ovicell and the absence of erect tubular spines seem suf- ficient to differentiate it. Possibly it may vary into robertsonae. O’Dono- ghue found it at several localities in British Columbia waters. It has not been noted in the Hancock collection. Genus DORYPORELLA Norman, 1903 This is a peculiar genus among the Alderinidae, as the reticulated gymnocyst is so extensive that it often limits the opesium so much that older authors placed the one species then known, spathulifera Smitt, under genera of Ascophora. Pore chambers are present ; small frontal avicularia; four to six distal spines. Ovicell hyperstomial, not closed by the opercul- um. Levinsen (1909:150) submerged this genus in Callopora but as the genera in the Alderinidae are now understood Doryporella appears to have a satisfactory basis. Genotype, Lepralia spathulifera Smitt, 1867 :20. 84 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Doryporella spathulifera (Smitt), 1867 Plate 8, figs. 4 and 5 Lepralia spathulifera Smitt, 1867 :20. Microporella spathulifera, Waters, 1900 :87. Doryporella spathulifera, Norman, 1903 ;106. Membranipora spathulifera, Levinsen, 1916 :441. Callopora spathulifera, Osburn, 1919 :608. Zoarium encrusting, especially on shells. The zooecia present a very unusual appearance for an anascan form. The gymnocyst extends over most of the frontal surface, occupying half or more of the proximal end and extending widely forward on either side of the aperture, the surface reticulated. ‘The opesia is quite variable in form, usually shaped some- what like a horseshoe, but may be a regular ellipse. ‘The gymnocyst and ovicell are granulated. A broad, lanceolate spine, jointed at the base, arises on the median line near the proximal border of the opesia, and just behind this is a small oval avicularium, also in the midline. There are 4 to 6 oral spines, the lateral ones sometimes enlarged at the base. At either side of the operculum is a small oval avicularium. The ovicell is hemispherical, hyperstomial but not prominent. Well distributed in high northern waters. In the Hancock collections there is a specimen from Cleveland Pas- sage, Frederick Sound, Alaska, 12 fms. Also common at Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. Doryporella alcicornis (O’Donoghue), 1923 Plate 8, fig. 3 Membranipora alcicornis O’ Donoghue, 1923 :26. A mphiblestrum alcicorne, O’ Donoghue, 1926:38. Zoarium encrusting on shells and pebbles. The zooecia are distinct with well-marked separating grooves, averaging about 0.45 mm in length by 0.30 mm in width. The proximal half of the zooecium is covered by a strongly reticulated gymnocyst which extends along the sides of the opesia, as in D. spathulifera. The opesia is rather regularly oval, ranging in length from 0.18 to 0.22 mm and in width from 0.16 to 0.18 mm, its rim thin and slightly raised. The cryptocyst is vestigial. At each distal “corner” is an erect, simple or bifurcate spine; on either side of the operculum another erect spine with 2 to 4 points, and toward the proximal end of the opesia there is another spine with 4 to 6 points which bends over the opesia. The avicularia are small, salient, with short-tri- angular mandible, situated on the gymnocyst at one side of the median No. | OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 85 line, and resembling those of D. spathulifera except that they are more elevated. The ovicell is prominent, globular, 0.18 to 0.20 mm in breadth, and its surface is reticulated like the gymnocyst. Pore chambers are present, as in D. spathulifera. O’Donoghue described the species in the genus Membranipora and later removed it to Amphiblestrum. It cannot, however, be associated with that genus as the calcified frontal enclosure is a gymnocyst and there is no evidence of an expanded cryptocyst. Aside from the spines its es- sential characters are those of D. spathulifera. It was recorded by O’Donoghue from numerous localities in British Columbia, from Victoria northward. A specimen in the Hancock collections is from Cadboro Bay, Victoria, British Columbia. Genus RETEVIRGULA Brown, 1948 Retevirgula Brown, 1948 :109. This genus has been recently established to include those membrani- porine species which are similar to Callopora, but in which the zooecia are more or less dissociated and united by tubular connecting processes ; which have mural spines; rounded vicarious avicularia on zooeciules oc- cupying a place in the zooecial series ; a hyperstomial ovicell with a frontal fenestra, and which are without dietellae. The genotype is Membranipora acuta Hincks, 1885 :249. The species have hitherto been distributed by various authors in Membranipora, Beana, Pyrulella, Mystriopora (?), Hincksina and Cauloramphus. The genus seems to have a closer relation to Pyrulella than to any other but the species of that genus have frontal avicularia and are without connecting tubules. Key To SPEcIEs OF Retevirgula 1. Zooecia large and broad, opesia oval, interzooecial fenestrae and zooeciules rather rare. . . lata Zooecia smaller and narrower, opesia ‘elliptical, fenestrae and zooeciules frequent. . . = Veta 2. Zooecia always disjunct and connected by tubules, with e con- spicuous fenestrae; the proximal 4 pairs of spines curved over the opesia. . . «5 On tebulata Zooecia disjunct or in contacts proximal eines lowe: not curved, but lean somewhat over the OPeStas sf a5. WA ee Greclata 86 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Retevirgula tubulata (Hastings), 1930 Plate 8, fig. 1 Pyrulella tubulata Hastings, 1930 :709. Pyrulella tubulata, Osburn, 1940 :14. Retevirgula tubulata, Brown, 1948 :110. The zoarium is thin and unilaminar, encrusting, but loosely attached by dorsal tubular processes. The zooecia are of moderate size with a considerable range, 0.45 to 0.60 mm long. In some zooecia there is a well developed smooth gymnocyst; in others this is almost wanting. The zooecia are disjunct and connected by tubes, but here there is also much variation and frequently the neighboring zooecia are in contact. Large fenestrae between the zooecia are common, but they are often small or wanting. The avicularia are vicarious on zooeciules which are connected to zooecia or to each other by tubules; mandible semicircular. The spines are usually 6 on each side, the distal pair directed forward, the following one or two erect and the rest bending over the opesia. The ovicell is about 0.18 mm wide, prominent, globular, with an upturned lip, and there is a large rounded fenestra situated somewhat distally on the top. Dr. Hastings described the species from the Galapagos Islands and recorded it also from Gorgona, Colombia. Our specimens agree closely with her description. Hancock Stations: 59-33, Charles Island, 310-35, Bindloe Island, 352-35, Chatham Island and 432, Albemarle Island, Galapagos ; 225-34, Gorgona, Colombia; 457-35; Secas Islands, Panama; 132-34, Socorro Island and 223, Clarion Island, west of Mexico; 125-33, Isabel Island, Mexico; 263 and 270, Angel de la Guardia Island, Gulf of California (the most northerly record) ; shallow water to 80 fms. Also Gulf of Panama, Galtsoff collection on pearl oysters. Retevirgula lata new species Plate 7, fig. 7 Zoarium thin, unilaminar, encrusting but very loosely attached, the dorsal surfaces of the zooecia bearing short attachment processes. Zo- oeciules of various sizes are frequent. The zooecia are large, 0.75 to 1.00 mm in length by 0.55 to 0.65 mm in breadth; distinct, their side walls usually in contact, but frequently more or less separated by small fenes- trae, in which case they are connected by short tubular processes. The gymnocyst varies greatly in extent and this accounts almost entirely for the variation in zooecial length; proximal to the opesia there is frequently No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 87 a blunt tubercle. The opesia is oval, large, about 0.65 mm long by 0.35 mm wide, the mural rim thin and the descending cryptocyst narrow and granulated. There are usually six spines on each side. Avicularia are few and widely scattered, vicarious on zooeciules, the chamber rather large (about 0.40 by 0.50 mm) ; the avicularium small, short oval, with an elevated rounded rostrum which is crenated on the distal edge ; the mandi- ble semicircular, with strong hinge denticles. The ooecium has a large circular membranous area on its distal end. This is not due to incomplete growth as the border of the fenestra is thickened and finely beaded and the same characters appear on all of the ooecia. The ooecium is very prominent, hyperstomial, broader than long, averaging 0.30 mm wide by 0.26 mm long, the surface smooth and shining, the proximal edge slightly elevated to form a lip, the aperture not closed by the operculum. Type, AHF no. 21. Type locality, Hancock Station 446, James Bay, James Island, Ga- lapagos Island, 54 fms. Also at Sulivan Bay, James Island, and at 450, 0°55’S, 90°30’W, Galapagos, 14 to 60 fms. Retevirgula areolata (Canu and Bassler), 1923 Plate 7, fig. 6 Mystriopora ? areolata Canu and Bassler, 1923:19. Zoarium thin, unilaminar, encrusting but loosely attached by the short dorsal tubercular processes of the zooecia; zooeciules of various sizes are of frequent occurrence. The zooecia, while often in contact on the sides, are in general more loosely attached to each other than in R. data; the fenestrae are larger and the connecting tubes longer. Zooecium moder- ately large, 0.65 mm long by 0.40 mm wide, the gymnocyst is usually well developed, narrowed proximally to the tubular process which con- nects it with the preceding zooecium. The opesia is distinctly narrower in proportion than in Zata, elliptical, averaging about 0.55 mm long by 0.26 mm wide. The mural rim is elevated, moderately thin and the cryptocyst narrow and granulated. There are 6 or 7 tall strong spines on each side, the two distal pairs erect and the others leaning somewhat over the opesia. There are also small spines on the avicularian rims. The avicularia are small, rounded, elevated, the mandible semicular and attached by strong hinge denticles. The ooecia are prominent, but difficult to see among the tall spines, globular and smooth, with a rounded or elliptical fenestra near the mid- _ dle of the front, width and length about 0.26 mm. 88 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 This species differs from R. Jata in the looser connection of the zo- oecia, the smaller size, the narrower opesia, the position of the ooecial fenestra and especially by the extensive development of the spines. This species was described from the Pleistocene of Santa Monica, California, by Canu and Bassler, who were uncertain as to its generic re- lationships. The ovicell and avicularium are lacking in their material, but the other characters correspond fairly well. Hancock Stations 1283-41, off Santa Rosa Island, California, 28 fms, 10 colonies on large coralline ; Redondo Beach, California, shallow water ; Point Vicente, California, 14 fms. Also Monterey Bay, California (Blagg collection). Family Chapperiidae Bassler, 1935 Represented by the one genus, Chapperia. Usually this genus has been associated with other membraniporine forms in the Anasca, but Canu and Bassler (1927) separated it widely and placed it under their new sub- order Hexapogona on what appears to be a very insufficient character, viz. ‘“The ancestrula engenders six zooecia.” It is true that the usual number of buds on the cheilostome ancestrula is five, but the number varies all the way from one to six among the encrusting species, and also varies somewhat within a single species. I have noted as few as four in one colony of Chapperia patula (Hincks), and six are occasionally found in other anascan species. The most unusual character of the group is the presence of ‘‘occlusor- laminae” (Harmer), a pair of horizontal projections arising from the lateral walls opposite the operculum and considerably beneath it. They afford attachment for the occlusor muscles of the large operculum; there is much variation in size and in some species they are scarcely noticeable, often obscured by the lateral cryptocyst above them; at their fullest development they may unite to form a continuous shelf around the distal end. Spines, simple, forked or cervicorn, are present on all of our species. Avicularia may be either sessile or pedunculate, and both types are sometimes present on the same colony. The ovicell is hyperstomial, prominent, cucullate and not closed by the operculum. Large multipor- ous septulae are located rather high in the lateral and distal walls. The general characters of this group appear to be anascan and I am therefore returning the Chapperiidae to the Anasca following the Al- derinidae, to which they seem to have the closest affinity. NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 89 Genus CHAPPERIA Willey, 1900 Willey 1900:5, (to replace Chaperia Jullien 1881, preoccupied). This genus has been the subject of much controversy and I shall not be able here to settle the disputed points. Jullien’s brief description is as follows: ‘““I'wo internal calcareous plates, with extremities fixed and serving for the insertion of the retractor muscles of the operculum” (transl. by Canu and Bassler). These plates lie beneath the anterior part of the opesia and usually fuse at their distal ends, sometimes form- ing a curved shelf. Spines, usually very strong, are present on the distal rim. Avicularia usually present, more or less fused with the distal rim. The operculum, usually well chitinized, occupies much of the opesia. The ovicell is prominent, conspicuous even among the spines, hyper- stomial and somewhat cucullate. Genotype, Flustra acanthina Quoy and Gaimard, 1825. Key To SPECIES OF Chapperia 1. Zooecia large (0.70 to 0.85 mm long), red or brownish, the mural rim widely flared... c. «2s «o>. patula Zooecia moderate in size, not over 0. 60 mm ‘long. 5) Sa paneer eae ene 2. Spines and frontal processes fuse to form a cover above the opesia. . . AS. ee DIOtaES Spines simple, not eS more or ce oe Pine as) 3. Spines very elongate and erect ; avicularia elevated on tall eae cels; no pigment. . . Si ae a Longesprna Spines not usually long, cuned! or ‘straight. : 4. Heavily red or brown pigmented ; spines stout, proximal pair curved over opesia; opesia broader than long: ‘ ‘cardelles”’ large. . . . condylata Slightly boar or ant at all pigmented ; spines straight; opesia longer than broad; “cardelles’ wanting. . . . . californica Chapperia patula (Hincks), 1881 Plate 10, figs. 1 and 2 Membranipora patula Hincks, 1881:150. Membranipora patula, Robertson, 1908 :263. Chapperia galeata, Canu and Bassler, 1923 :52 (part, Pl. 34, figs. 9, 10). Membranipora patula, O’Donoghue, 1923 :25. Amphiblestrum patulum, O’Donoghue, 1926 :37. The zoarium forms rough, reddish brown or reddish purple incrusta- tions on almost anything that will afford attachment, occasionally even on stems; loosely attached, the dorsal side with rough protuberances which have no regularity. The zooecia are large, 0.70 to 0.85 mm long by 0.50 to 0.75 mm wide, ogival in form, the mural rim on the sides expanded, somewhat saucer-shaped, and the distal rim much raised and 90 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 thick. The membrane covers the whole frontal surface, as the gymnocyst is vestigial. The heavily calcified, granular cryptocyst is broad proximally and extends around the opesia, narrowly on its distal border. The opesia occupies about half the length of the front, more or less rounded, but usually a little broader than long (length 0.30 to 0.38 mm, width 0.33 to 0.40 mm). Within the opesia, below its distal border is a calcified shelf, the “‘occlusar-lamina” of Harmer, to which the opercular occlusal muscles are attached. Just above the proximal ends of these laminae are rounded knobs, often wanting, which present the appearance of cardelles, but as they lie much below the level of the operculum, even in the contracted state, their function is problematical. There are four or six tall tubular spines, with dark joints, on the distal rim; rarely one of these is short-bifurcate. The avicularia are proportionately small, median, triangular, fused with the border of the distal rim and pointing forward (length 0.15 to 0.18 mm) ; often wanting and apparently never present when there is an ovicell. The ooecia are large, 0.38 to 0.42 mm wide by 0.26 to 0.30 mm long, hyperstomial, cucullate with a wide open front ; the ectocyst does not quite cover the endooecium and leaves a crescentic area next to the border. Hincks described the species from California and the Queen Char- lotte Islands; Robertson listed it from southern California, and O’ Dono- ghue from numerous localities in British Columbia. In the Hancock collections it is abundantly represented at 38 stations, from the coast of Oregon to Thurloe Head, Lower California; from shallow water to 47 fms. Chapperia condylata Canu_and Bassler, 1930 Plate 10, fig. Chapperia condylata Canu and Bassler, 1930 :44. The zoaria form reddish to deep purple irregular incrustations on various objects. The zooecia are moderate in size, 0.35 to 0.45 mm wide by 0.40 to 0.50 mm long, ogival in form, the mural rim erect and not spreading out laterally as it does in C. patula. The gymnocyst is vestigial, only large enough to support the avicularia in the proximal corners; the cryptocyst broad proximally and extends forward around the sides of the opesia. The mural rim is moderately thick and elevated on the distal border. The opesia is noticeably transverse, 0.28 to 0.30 mm wide by 0.18 to 0.22 mm long, though occasionally more nearly round. Within the opesia are the ‘‘occlusar-laminae”’ and at their proximal ends are NO. 1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 91 rounded knobs, the “condyles” of Canu and Bassler, which as in C. patula appear to be too far below the level of the operculum to serve as hinge denticles; they are often wanting. The avicularia are usually paired in the proximal corners, triangular and directed forward or laterally. When ooecia are present the avicularia are more or less fused with the ectooeci- um and are directed proximally or laterally. In addition there is often a larger frontal avicularium with a longer triangular mandible; this is occasionally mounted on a tall peduncle. Six distal spines with black joints. The ooecia are hyperstomial, prominent, with the usual crescentic area around the orifice, length 0.18, width 0.26 mm. Described by Canu and Bassler from the Galapagos Islands. Distributed along the coast and about the islands from Santa Cata- lina Island, southern California, to Colombia and the Galapagos Islands; Thurloe Head, Lower California; San Francisco Island, Gulf of Cali- fornia; Petatlan and Tenacatita Bays, Mexico; Socorro Island, west of Mexico; Pinas Bay, Panama; taken at 28 stations, most common about the Galapagos Islands. Shore to over 100 fms. Chapperia californica new species Plate 10, fig. 5 Chapperia galeata, Canu and Bassler, 1923:52 (part, Pl. 34, fig. 8, but not figs. 9 and 10 which are C. patula). Zoarium encrusting stems, or bilaminate, white to reddish brown. Zooecia moderate in size, 0.45 to 0.60 mm long by 0.35 to 0.40 mm wide, often elongate and narrowed proximally; the mural rim thin and high and somewhat flaring in the sides, elevated distally. ‘The cryptocyst broad proximally, continued around the sides of the opesia, granulated. Opesia short elliptical, oval or rounded, but averaging longer than broad, 0.35 to 0.40 mm long by 0.25 to 0.35 mm wide. The occlusar-laminae beneath the distal end of the opesia are rather long, their borders nearly straight and converging at the distal end. The spines are 4 to 6 in number, tall and slender, jointed at the base and more or less directed forward or erected. The avicularia, frequently wanting, are sessile or slightly elevated, median, directed distally, the mandible short to long triangular (0.08 to 0.18 mm long), with small cardelles; always absent distal to an ooecium. The ooecium is hemispherical, cucullate, prominent, hyperstomial, with a wide aperture. The usual crescentic area is present above the aper- ture. The ectooecium is transversely lightly rugose and there are longi- tudinal small striae, making a faint lattice-work on the surface. 92 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 There is considerable resemblance to C. galeata (Busk), especially in form of the opesia and the arrangement of the spines, but in the speci- mens figured and described by Busk and by Jullien from the Falkland Islands (Iles Malouines) the ovicell is always covered distally by an avicularium which presents the form of a crest on the galea. There are no avicularia associated with ovicells on the several colonies which I have studied. Also I find no mention of the decoration of the ectooecium in C. galeata. The figure presented by Canu and Bassler (1923, pl. 34, fig. 8) of Pleistocene specimens from California show no avicularia associated with the ovicells. Type, AHF no. 22. Type locality, off San Pedro, California, several colonies encrust- ing hydroid stems and small worm tubes. In addition there is a bilaminate colony from Station 1250-41, one mile south of San Benito Island, off the coast of Lower California, 28°17’N, 115°35’40”W, at 49 fms; and Stations 1187-40 and 1431-41, off Santa Catalina Island, California. Also a specimen from the Lower Pleistocene at ‘Timm’s Point, California (San Pedro), collected by G. P. Kanakoff. Chapperia frontalis new species Plate 10, fig. 4 This is a remarkable little species, characterized by the fusion of spinous processes to form a sort of pericyst high above the opesia and extending forward over the aperture and ooecium. Ihe zoarium is en- crusting, small, white and shining. The zooecia are small (0.40 mm long by 0.25 mm wide) and very deep so that the zooecia appear to stand almost on end. The opesia is transversely oval, somewhat straighter on the distal border, 0.20 mm wide by 0.15 mm long, its border smooth and little raised. The occlusar-laminae within the aperture are narrow and diagonal. ‘he gymnocyst is short and bears a raised median avicularium with a triangular mandible directed upward and backward. The crypto- cyst is a moderate, smooth shelf, extending forward on the sides to the level of the operculum. The striking feature of this species is found in the nature of the fenestrated frontal cover like a pericyst high above the opesia. There is a pair of long flattened spines opposite the operculum which curve up- ward and forward, the tips meeting and often fusing. From around the base of the avicularium about 5 (4 to 6) flat, hollow processes extend in a radiating manner, sometimes bifurcating, and fusing with each No.1 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 93 other at their tips and also with the large lateral-oral spines to form a shield in which there are several (3 to 5) elongated fenestrae. In addi- tion there is a pair of widely separated distal oral spines which are round and more or less erect; when ooecia are present these spines fuse to some extent with the sides of the ovicells. The ooecium is characteristic of the genus, large (0.20 mm wide), prominent, cucullate and wide open at the aperture, smooth, and the ectooecium is not quite complete leaving a triangular area immediately above the opening. The fused tips of the lateral-oral spines sometimes extend beyond the ovicell. Reproduction begins early in the colony forma- tion with the second or third row of zooecia; the largest colony consists of only 36 zooecia of which 24 bear ovicells. The ancestrula is membraniporoid, the opesia occupying the whole of the front, and with 3 rather strong erect spines on each side. Type, AHF no. 23. Type locality, Sta. 473, off Hood Island, Galapagos, 1°22’40”S, 89°37/00”W, 75 fms, two colonies on a cinder. Also at Sta. 461, off Tagus Cove, Albemarle Island, Galapagos, 80 fms, one colony on a coral fragment; and Sta. 406, 1°03’30”S, 90°17’30’W, 60 fms, one colony on a coralline fragment. Chapperia longispina new species Plate 10, figs. 6 and 7 Zoarium encrusting, white, the zooecial characters, obscured by the close array of tall, slender white spines. The zooecia are of moderate size, 0.45 to 0.60 mm long by 0.40 to 0.45 mm wide; closely set; the walls high but not conspicuously flaring. The gymnocyst is usually limited to the area covered by the base of the avicularium; the cryptocyst broad proximally, decreasing in width to the level of the operculum; the opesia is more or less rounded (about 0.30 mm in each dimension), the occlusar- lamina moderately developed and no indication of condyles. There are usually 4, occasionally 6, tall, tubular oral spines, slender only in com- parison with their length, the longest measuring as much as 0.90 mm, the average being about 0.70 mm. The spines are all nearly erect, never more than slightly curved, and the distal pair is not lost in the presence of an ovicell. The avicularia are of two kinds. In the absence of an ovicell the avicularium on the basal gymnocyst is only slightly elevated and has a short-triangular mandible. When an ooecium is developed, the avicu- larium distal to it rises in tubular form to the height of the ooecium; the 94 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 mandible is irregularly spatulate and broadened at the tip; the edge of the rostrum often becomes irregularly spinulose. Also from the base of the avicularian chamber lateral furcate spinose processes are developed. ‘The erect chamber or pedicel may be free or it may be fused with the ectooecium. Its nature is very similar to that described by Busk (1884: 78) and Waters (1888:12) for C. (Electa) cylindracea. The ovicell is typical of Chapperia, rounded, prominent, cucullate, smooth, but the ectooecium is more complete than in most other species ; it measures about 0.26 mm in width. By the similarity of the avicularia this species appears to be most nearly related to C. cylindracea (Busk) from the Indian Ocean, but it differs in the nature of the spines which are much longer and entirely unmodified ; in the absence of a widely flaring mural rim, and in the nar- rower cryptocyst, as well as in the form of the avicularian mandible. Type, AHF no. 24. Type locality, Hancock Sta. 1385-41, 13 miles SSE of East Point, Santa Rosa Island, southern California, 75 fms. Two colonies, one en- crusting a hydroid stem and the other on a shell fragment. ? Chapperia varians (O’Donoghue), 1923 Membranipora varians O’ Donoghue, 1923 :29. Chaperia varians (O’Donoghue), 1926:40. The generic relationship of this species is in doubt, due to the lack of important characters in the description. Ovicells were not found and there is no mention of the nature of the communication pores nor of the method of attachment of the opercular muscles. O’Donoghue transferred it from Membranipora (where it cannot belong) to Chapperia at Waters’ suggestion, but it might as well be a Callopora or Hincksina. Whatever it is, it appears to be a good species, and I append a brief list of the characters in the hope that some one may later recognize it and have sufficient material to complete the description. A smooth thin cryptocyst occupies about one-third of the frontal area; the opesia is oval with a thin, low rim and occupies nearly all of the remaining front; a few small lateral and distal spines are present; a proximal avicularium is borne on a short truncated conical base in the midline (suggesting Chapperia) and a minute stalked avicularium is situated on either side opposite the operculum. Off Protection Gap and off Snake Island, British Columbia (O’Donoghue). No. l OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 95 Family Arachnopusiidae Jullien, 1888 An arched calcified frontal shield or pericyst which is perforated by numerous large pores above the membranous ectocyst. The pericyst is formed by irregular projections originating from the lateral and proximal margins. Levinsen (1909:160) states that the projections in Arachno- pusia are at first hollow spines which later become solid. In the other two genera here considered there is no evidence of hollow spines at any time. There is much uncertainty whether these two genera belong with Arachnopusia, and also whether the family is properly placed. It is pos- sible that it should be included among the cribrimorphs, but the pericyst is not formed of parallel or radial costae. Genus EXECHONELLA Canu and Bassler, 1927 “The frontal pores are orbicular. A peristome very much developed, surrounds an orifice closed by a true operculum. The ectocyst is hidden under the frontal” (Canu and Bassler, 1926:4). Genotype, Hiantopora magna MacGillivray, 1895. The external appearance is that of a member of the Ascophora, but careful dissection exposes the ectocyst which covers the full breadth of the opesia beneath the pericyst. The dorsal wall is provided with tubular processes for attachment. Exechonella antillea (Osburn), 1927 Plate 10, figs. 9 and 10 Lepralia antillea Osburn, 1927 :128. Exechonella pumicosa Canu and Bassler, 1928 :70. Exechonella antillea, Osburn, 1940 :366. Zoarium encrusting on shells, corals, etc., forming a coarse yellowish or grayish layer; attached by dorsal processes, one or more on each zo- oecium. Zooecia large, 0.70 to more than 1.00 mm in length by 0.60 to 0.70 mm in width; well separated by deep grooves even in older stages. The whole area of the gibbous pericyst is coarsely perforated, each pore being surrounded by a broad collar. A thick-walled peristome, usually considerably elevated but lower on the proximal border, often bearing tubercles, and occasionally the whole rim flared outward. The aperture is large, about 0.20 to 0.25 mm in either dimension, varying in form but usually slightly quadrate with the corners rounded. The operculum is 96 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 well chitinized, with a pair of strong sclerites which reach forward from the heavy cardelles; it is complete on the proximal border, but is attached to the ectocyst from which it is easily separated; in dried or alcoholic specimens the contraction usually detaches it from the ectocyst. There is a row of uniporous septulae in the lateral and distal walls. No ovicells. Osburn described the species from Curacao Island in the southern Caribbean Sea and in the following year, before the description of antillea was available, Canu and Bassler named it pumicosa from southern Florida. It is widely distributed in the West Indian region. Pacific coast specimens appear to agree in every particular. Albatross Stations: D.2824 and D.2825, Gulf of California. Genus ANEXECHONA new genus Zoarium encrusting, often multilaminar, rarely with erect, flat branches. Frontal wall a pericyst, with large funnel-shaped pores, above the frontal membrane or ectocyst which covers the whole opesia; peri- stome wanting, the operculum on a level with the zoarial surface; side walls with multiporous, the distal wall with uniporous septulae. Avicu- laria large, vicarious, occupying a place in the zooecial series. No spines nor tubercles. No ooecia. Genotype, Anexechona ancorata Osburn, new species. This genus is evidently related to Exechonella by the manner of form- ing the porous pericyst, which grows inward from all sides without any evidence of spines. It differs in the absence of a salient peristome, in the nature of the operculum, and in the presence of large vicarious avicularia. Since Canu and Bassler selected the name Exechonella because of the raised peristome, I am adopting Anexechona, not salient, for the present genus. Anexechona ancorata new species Plate 11, fig. 1 The zoarium encrusts shells, stones and occasionally algae; often several layers in thickness, rarely erect and bilaminate, back to back; dorsal surface smooth; frontal surface flat and smooth; light yellow to brownish in color. Zooecia distinct, but the interzooecial grooves very shallow; the brown opercula and avicularian mandibles standing out prominently. The zooecia are large, 0.65 to 0.80 mm long by 0.40 to 0.50 mm wide; the frontal nearly flat, consisting of a smooth pericyst with large in- fundibular pores evenly arranged. The region about the aperture is No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 97 slightly higher, but there is no peristome and the operculum is at the level of the frontal surface except at the proximal border where it drops slightly below. The aperture is large, about 0.18 mm long by 0.20 mm wide, subquadrangular, nearly straight on the sides with the proximal and distal borders slightly arcuate; the strong cardelles situated about one-third of the way from the proximal border. The operculum is brownish with a heavy dark brown band continuous around the border; proximally it is attached to the ectocyst but is easily separable from it. The avicularia are unusually large, interooecial, scattered, occupy- ing a place in the zooecial series, the chamber 0.60 to 0.80 mm long by 0.40 to 0.50 mm wide; the dark brown mandible usually from 0.40 to 0.50 mm long, spatulate in form, with 3 strong unguiculate teeth at the end and 2 or 3 smaller ones along the sides, somewhat resembling a grappling hook; it is broadened at the base and attached to a strong pivot. No ovicells, no spines. Type, AHF no. 25. Type locality, Hancock Station 1049-40, Angel de la Guardia Island, Gulf of California, 29°32’47”N, 113°34’35’”W. Also dredged at Sta- tions 650-37, San Francisco Island and 2180, off Magdalena Bay, Gulf of California; 136-34, Clarion Island, west of Mexico; 217, Tenacatita Bay, Mexico; 468-35, Port Parker, Costa Rica and ‘off Colombia.” Also Albatross Sta. D.2825, Gulf of California. Shore to 50 fms. Family Hiantoporidae MacGillivray, 1895 In the genus Hiantopora MacGillivray, 1887, there is a pericyst formed by the fusion of branching spines above the ectocyst; these often form an almost complete cover, with large irregular pores. Marginal and interzooecial avicularia may be present. Dorsal tubular processes are for attachment. The ovicell is not closed by the operculum. Tremopora Ortmann, 1890 is similar in appearance to Hiantopora, but the spines are less developed, the ectocyst more exposed, and the ovi- cell is closed by the operculum. In Tremogasterina Canu, 1911, the pericyst is formed in a different manner, there is no evidence of origin from spinous processes and the front is solidly bridged over except for the presence of 2 or 3 large central pores. The ovicell is hyperstomial and closed by the operculum. The first two genera are apparently closely associated, but Tremo- gasterina differs so much that its position is questionable. Like the cribri- morphs and the Arachnopusiidae it has an external resemblance to the Ascophora, but the ectocyst extends over the opesia beneath the pericyst. 98 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Genus TREMOGASTERINA Canu, 1911 The ovicell is hyperstomial and closed by the operculum. The aper- ture bears two small cardelles; the operculum, often chitinized, is at- tached to the ectocyst. The frontal is a pericyst extending over the ecto- cyst or frontal membrane; the central area is perforated by 2 or 3 large reniform or rounded pores. Large avicularia arise from the lateral walls and assume an interzooecial appearance. Genotype, T. problematica Canu, note Tremogasterina granulata var. subspatulata new variety Plate 10, fig. 8 Zoarium encrusting, usually on sponges, usually unlaminar, white to light yellow in color, often covering several square inches. Zooecia ventricose, distinct with deep separating grooves in the young stage, but becoming nearly level with increased calcification. On both sides and around the proximal end there is a row of rather large rounded pores, resembling the areolar pores of the Ascophora, and from the distal pore on one side arises the avicularian chamber; with increased calcifica- tion the frontal outlets of the pores of neighboring zooecia usually unite so that there seems to be but one row, a fact which no doubt explains the statement of Canu and Bassler (1929:119) in regard to T. celle- poroides (Busk) that “there is only a single range (of pores) between two adjacent zooecia.” In balsam mounts of marginal zooecia the two rows are very distinct in the youngest zooecia and in older ones the separate pores may be seen at the bottom of the single opening. Even the secondary pores often become completely closed off in older zooecia. The frontal is a pericyst, above the frontal membrane, and appears to be formed in a different manner than any other pericyst. Acicular spicules are laid down inside from the zooecial walls, at first conforming to the “areolae,”’ then becoming concentric about the central pores, while more distally they conform to the aperture and even extend around it on the distal border. When first formed this layer is thin and smooth, but it very soon becomes heavily calcified and much roughened, and the fur- rows between the zooecia are filled ; the depression about the central pores remains evident at all stages. The whole process resembles the formation of the olocyst and pleurocyst of the Ascophora, as first stated by Canu and Bassler (1928:44) and later (1929:117) corrected by them. The aperture is somewhat quadrate, the sides straight, the distal end rounded, the proximal end slightly arcuate and broader, length 0.22 to 0.26 mm, width 0.18 to 0.20 mm; peristome low and very thin with 2 No. 1 OSBURN : EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 99 to 4 small distal spines; a pair of strong cardelles; the pericyst forms a thick, low wall around the peristome but without fusing with it. The operculum is well chitinized, with a narrow border and a pair of heavier sclerites which extend forward from the cardelles within the lateral borders and meet at some distance back of the distal border. The opercul- um is connected with the frontal membrane, but is detachable. The large elongate avicularia are so regularly disposed between the zooecia that they appear to alternate with them in series, but they are interzooecial only in arrangement and not vicarious, as shown by their manner of budding and by the fact that the avicularian chamber does not descend below the level of the primary layer of the pericyst. The mandible is elongate and narrowly spatulate, its tip much decurved with its point usually fitting into the central depression; a triangular lucida in its base, and hinged to strong cardelles which occasionally meet to form a bar; the mandible measures 0.35 to 0.50 mm long by 0.13 to 0.16 mm wide at the base. The ovicell is rounded, about 0.25 to 0.30 mm wide; at first promi- nent, but later becoming immersed, the surface roughly reticulate; closed by the operculum. There is close agreement between the typical granulata Canu and Bassler, 1928 :45, from the Florida Straits, and the present variety in all points, except in the avicularia which are broader, the sides parallel to near the tip which is suddenly rounded at the hooked beak. Type, AHF no. 26. Type locality, Hancock Station 136-34, Clarion Island, 18°20’05”N, 114°44’40”W, 32 fms. Also at Station 137-34, Clarion Island, and 539 -36, Angeles Bay, Lower California, 20 fms. Division II COILLOSTEGA Levinsen, 1909 In this group the horizontal lamina of the cryptocyst is highly de- veloped, in some cases even extending forward around the aperture, and above this lies the frontal membrane. The lateral muscles which operate the membrane pass downward to the dorsal wall distally to the lamina, or through notches at the sides, or through special foramina at either side known as the opesiules. When the opesiules are well developed the distal end of the polypide is more or less enclosed in a calcified polypide tube. Avicularia or vibracula are usually present and always interzooecial. Ooecia may be either hyperstomial or endozooecial. 100 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Key To FAMILIES 1. ‘Ovicells hyperstomrale Vio ee Se Ovicells endozooecial or wanting. . . wis 2. Ovicells very large, very prominent; apenas lass eclene zooecia; opesiules closed. . . . . . . . Thalamoporellidae Ovicells normal in size and appearance; opesiules joining the opesia (sometimes scarcely a eee ; avicularia smaller (sometimes wanting) . . . 3. ew. | Semihaswellia Genus CYLINDROPORELLA Hincks 1877 Zoarium encrusting. Zooecia more or less terete, the proximal end usually much narrowed, the distal end elevated into a high tubular peristome which bears a small tubular ascopore near its base. Frontal with numerous small pores. Ooecium hyperstomial. No avicularia, no spines. Genotype, Lepralia tubulosa Norman, 1868. Cylindroporella tubulosa (Norman) 1868 Plate 35, fig. 2 Lepralia tubulosa Norman, 1868 :308. Porina tubulosa, Hincks, 1880 :230. Porina tubulosa, Osburn, 1912 :233. Cylindroporella tubulosa, Osburn, 1933 :34. Zoaria encrusting, usually small, on shells. The zooecia are some- what terete, the proximal end often narrowed to a point, very dis- tinct, the front ventricose and perforated with numerous small pores. 304 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 The distal end rises into a long thin tubular peristome which bears a small tubular ascopore near the base on the proximal side. No avicularia and no spines. The hyperstomial ovicell is situated low down on the distal side of the peristome. North Atlantic and Arctic Oceans from Spitsbergen west to Dolphin and Union Straits, Northwest Territory, Canada; on the Atlantic coast it ranges as far south as Cape Cod. I have found no record of its occur- rence in the Pacific Ocean. Cordova, Alaska, Albatross, June 28, 1914; Punuk Island, Bering Sea, 15 fathoms; Port Etches, British Columbia, from specimens in the Los Angeles Museum, with no other data. Common at Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector. It is evidently a circumpolar species. Genus SEMIHASWELLIA Canu and Bassler, 1917 Zooecia on only one side of the erect zoarium; the dorsal side bears only avicularia. Frontal and dorsal sides of the same nature, formed of a tremocyst with sulci. A spiramen or “ascopore” below the base of the peristome. (After Canu and Bassler, 1917:58.) Genotype, Porina proboscidea Waters, 1889. Semihaswellia sulcosa Canu and Bassler, 1930 Plate 35, fig. 3 Zoarium erect, branching dichotomously, without joints. Zooecia gigantic, indistinct; deep longitudinal sulci, with large vacuoles at the bottom; peristome long, cylindrical, oblique, thick, sharp edged, its aperture orbicular. Ascopore tubular, salient, directed proximally. Small orbicular avicularia (?) on the front, and small dorsal avicularia. The zooecia measure 2.75 mm long by 1.00 mm wide and the peristome 0.45 mm high. (After Canu and Bassler 1930:15.) Described from the ‘‘Albatross” dredgings, ‘Galapagos Islands, D. 3048.” Hancock Station 481, Cartago Bay, Albemarle Island, Galapagos, 12 fms, several small branches. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 305 Family Stomachetosellidae Canu and Bassler, 1917 Frontal wall a very thick tremocyst or pleurocyst, built up around the aperture and notched to form a spiramen which is sometimes guarded by small avicularia. Primary aperture simple, without lyrula and usually without cardelles. Ovicell hyperstomial, deeply embedded. The original description of the family has had to be modified to include other genera than Stomachetosella which have been assigned to this family. The genera here treated may be distinguished by the following key: 1. Frontal a tremocyst with wide-mouthed pores . . . ... . 2 Frontal a pleurocyst with areolar poresonly ...... °. 3 2. Proximal border of the aperture with a sinus . . Stomachetosella Proximal border of the aperture without asinus . . . Pachyegis 3. Zoarium with cylindrical branched stems, zooecia on all SMdes paws Vl we ee . « « a Diatosula Zoarium encrusting or erect wih eened bilaminate lobes or diate, Wy a" PSP, is. ei oe.) ec eats: Cah coe STNG Ra mn CO ae Hippoporina porcellana (Busk), 1860 Plate 41, figs. 1-3 Lepralia porcellana Busk, 1860 :284. Lepralia cleidostoma Smitt, 1873 :62. Lepralia cleidostoma, Waters, 1899 :10. Lepralia porcellana, Norman, 1909 :305. Hippoporina cleidostoma, Canu and Bassler, 1928 :104. Hippoporina porcellana, Hastings, 1930:721. Hippoporina cleidostoma, Canu and Bassler, 1930:18. Hippoporina porcellana, Marcus, 1937 :96. Hippoporina porcellana, Osburn, 1940 :428. The zoarium is encrusting, usually on shells, white and glistening. The younger zooecia are distinct, rhombic in form and a little inflated, but with age the thick crust becomes nearly flat and obliterates the out- lines. The frontal is a thick olocyst with only a few areolar pores, smooth but with complete calcification, it is decorated with low, rounded granules. The primary aperture is round to the long cardelles, which are directed No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 345 slightly backward, and proximal to these is a deep and broad sinus or poster, the whole aperture having a “key-hole” form. There is a well developed vestibular arch which is sometimes faintly beaded. The peri- stome is low, in older zooecia submerged below the level of the surround- ing frontal crust. The operculum has the form of the aperture, with a complete sclerite extending around from one cardelle to the other at a distance from the border. Pointed avicularia are present, usually on one or both sides opposite the aperture, but often wanting. Dietellae. The ovicell is hyperstomial, imperforate, not closed by the operculum; prominent when young, with longitudinal striae; later with a semi- circular area above the orifice, but the whole ovicell becomes embedded in the thick frontal wall of the distal zooecium and completely buried within it when calcification is complete. There is much variation in the size of the zooecia, those near the center of the zoarium being much smaller than the outer ones. Typically the avicularia are located near one or both sides of the aperture and directed forward and laterally, but they may have any position on the frontal and be turned in any direction, all on the same colony. Descrip- tions and illustrations of this species do not indicate any areolar pores, but calcined specimens always show a few. In complete calcification there is often a small rounded umbonate swelling near the aperture. The synonymity of cleidostomata Smitt with porcellana Busk has been dis- puted, but Norman (1909:305) examined Busk’s type in the British Museum and states that “it proves to be a somewhat overgrown speci- men of Smitt’s L. cleidostomata.” After observing the wide variation in the supposed diagnostic characters of numerous Atlantic and Pacific specimens I am unable to separate them. It is a warm water species, recorded from the Mediterranean Sea and the Madeira Islands; on the Atlantic coast from Florida to Santos Bay, Brazil; and on the Pacific coast from the Galapagos Islands and Peru northward to southern California. Hancock Stations. An abundant species, occurring at 66 stations. The most southerly record is for Callao, Peru, and the northerly for Santa Cruz Island off southern California; coastwise it was taken also in Ecuador, Panama, Costa Rica and Mexico at various places, and off shore at the Galapagos, Socorro and Clarion Islands. 346 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Hippoporina tuberculata new species Plate 43, fig. 10 Zoarium encrusting on a shell. Zooecia small, 0.40 to 0.45 mm long by 0.25 to 0.35 mm wide, moderately distinct, ovate and arranged in quincunx; the frontal is a granulated pleurocyst, little inflated, with a few small inconspicuous areolar pores. The aperture is elongate, about 0.12 mm long by 0.09 mm wide, the anter somewhat pyriform, the cardelles very strong, pointed and directed backward, the poster broadly arcuate and varying in width; the operculum has the form of the aper- ture, well chitinized with a narrow sclerite paralleling the border. The peristome is low, thin, smooth, without spines and is not covered by the surrounding frontal wall. Small frontal avicularia are rare. The most unusual feature for this genus is the presence of low conical tubercles, one of these usually occupies the position of a median suboral umbo, one to three on each side of the aperture and one or more on the frontal. Dietellae are present. Ovicells are wanting on our small specimen. It is similar in most respects to H. porcellana, but the measurements are all smaller, the poster wider and shallower, and the conical tubercles give the frontal a very different appearance. Type, AHF no. 68. Type locality, Hancock Station 438, Chatham Island, Galapagos, 0°46’10”S, 89°30’10”W, at 35 to 40 fms. One small colony. Hippoporina contracta (Waters), 1899 Plate 41, figs. 4-5 Lepralia contracta Waters, 1899:11. Lepralia serrata Osburn, 1912 :242. Lepralia contracta, Norman, 1909 :306. Lepralia contracta serrata, Osburn, 1914:211. Perigastrella contracta, Canu and Bassler, 1920:576; 1929 :403. Perigastrella contracta, Hastings, 1930 :722. Perigastrella contracta, Marcus, 1937 :98. Hippoporina contracta, Osburn, 1940 :428 ; 1947 :33. Zoarium encrusting, often multilamellate, sometimes rising into ridges or frills. The zooecia are ovate or hexagonal, distinct when young but later immersed in a common crust. The front is a granular olocyst (? pleurocyst), thick, vitreous, with irregular tuberosities and marginal areolae. The aperture is somewhat elongate, rounded distal to the strong cardelles which are often more or less bifid; proximal to the cardelles NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 347 is a moderately broad and deep sinus or poster, semicircular in form. The vestibular arch is well developed and beaded. The primary peristome is low and smooth, but the frontal forms a secondary peristome which is irregularly thickened and often mucronate or umbonate on the proximal border in full calcification ; 4 to 6 oral spines are usually present. Avicu- laria are numerous and various, ovate to spatulate or pointed in form, oral or frontal, immersed or mounted on mamillate processes, the aper- ture beaded like the oral margin. Dietellae are present. The ooecia at first are prominent, embedded only in full calcification ; with a large semicircular and lightly striated area above the orifice which is not covered by the secondary calcification ; the wall eventually becomes very thick and irregular. In secondary calcification this species varies greatly, but the primary characters are quite constant, except for the form and position of the avicularia. The zooecia near the middle of the colony are much smaller than the later ones, graduated from about 0.30 to 0.60 mm in length, and the ovicell also varies from 0.15 to 0.18 mm in width. The reasons for transferring this species to the genus Hippoporina have been given by Osburn (1940:429), the nature of the frontal, the form of the aperture, the structure of the operculum, the arrangement of the avicularia, and the nature of the ovicell. ‘The species was described from Madeira. It is an abundant form on the Atlantic coast from Cape Cod, Massachusetts to the Bay of Santos, Brazil. Recorded also on the Pacific coast from Gorgona, Colombia, and from the Galapagos Islands by Hastings. Hancock Stations: Taken at 62 stations from Ecuador to the Gulf of California, abundant about the Galapagos Islands and Clarion Island. Hippoporina ampla new species Plate 41, figs. 6-8 The zoarium is encrusting on shells and corallines, white and glisten- ing. The zooecia are large, 0.90 mm long (0.70 to 1.10) by 0.80 mm wide (0.65 to 0.95), very distinct with deep grooves even in complete calcification, somewhat hexagonal in form. The frontal is a granular pleurocyst with 2 or 3 rows of pores and a large central imperforate area; in advanced calcification some of the granules on the proximal area become elevated into short, erect, pointed processes. The aperture is more or less removed from the distal border, pyriform, with sharp cardelles directed backward, and proximal to these is a moderately broad poster; 0.18 to 0.20 mm long by about 0.16 mm wide, the poster 0.10 348 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 to 0.13 mm wide; vestibular arch present; peristome low with about 8 oral spines; only in very advanced calcification does the frontal wall fuse with the peristome. The operculum has the form of the aperture, yellow and well chitinized, with a broad curved sclerite extending for- ward. The avicularia are comparatively minute, one on either side and distant from the aperture, pointed and directed laterally, and another pair of similar size and form about halfway back on the frontal, well separated and directed proximally. The ovicell is correspondingly large, about 0.45 mm wide and long, hemispherical, hyperstomial and not closed by the operculum, the texture of the very thick wall similar to that of the zooecial front. This species is a veritable giant among the others of the genus. As a rule in this genus there is only one row of areolar pores, but the nature of the aperture, operculum and ovicell appear to ally this species with Hippo porina. Type, AHF no. 69. Type locality, Hancock Station 438, Chatham Island, Galapagos, no additional data. Also at Stations 442, James Bay, James Island; 471, one-half mile north of Black Beach, Charles Island; 452, Post Office Bay, Charles Island ; and 171-34, off Stephens Bay, Chatham Island, all from the Galapagos at 18 to 65 fms. Genus HIPPOPORELLA Canu, 1917 Hippoponella Canu and Bassler, 1920 :379, is a pure synonym. The frontal is a thick, vitreous, granulated pleurocyst with a row of areolar pores. The aperture is broad proximally, slightly arcuate on the proximal border and approximately as wide as the anter; the cardelles strong and set well back; the vestibular arch usually delicately beaded. Peristome low and thin with 2 to 4 small spines. Dietellae present. Ovi- cell hyperstomial, not closed by the operculum, hemispherical, imperfor- ate, often becoming completely immersed. Genotype, Lepralia hippopus Smitt, 1867. This genus, which resembles Hippoporina in many respects, is easily differentiated by the form of the aperture. Hippoporella gorgonensis Hastings, 1930 Plate 45, figs. 10-12 Hippoporella gorgonensis Hastings, 1930 :723. The zoarium encrusts shells, etc., multilaminar and rough with mamillate or knob-like processes. Zooecia moderate in size, the young marginal ones 0.40 to 0.50 mm long by 0.25 to 0.40 mm wide, inflated No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 349 and the distal end somewhat elevated, arranged in quincunx; in the secondary layers the zooecia are partially erected and turned in every direction. The frontal is a pleurocyst with a row of areolar pores (often difficult to see and occasionally there are a few additional pores), smooth or granulated in the young but becoming exceedingly irregular with ridges and high tubercles. Normally there is a pointed umbonate process proximal to the aperture and one on each side (sometimes spine-like) and often there are others on the frontal. The aperture is lepralioid, rounded in front of the strong cardelles, broadest proximal to the cardelles and broadly arcuate, about 0.12 by 0.12 mm. The vestibular arch is often delicately beaded. The primary peristome is low and thin, with 2 to 4 small spines; with secondary calcification the spines disappear and the peristome is covered by the encroaching frontal wall. As indicated by Hastings, there are two kinds of opercula, one with sinuous sclerites and the other with thick bordering sclerite which is produced downward; muscle attachments are at the distal ends of the sclerites. The avicularia vary exceedingly; often there is a small rounded one asymmetrically situated at the base of the umbo and included in the secondary aperture, the lateral processes may be replaced by small round or pointed avicu- laria, and frontal avicularia, round or pointed, large or small, may occur on the frontal. The ovicell is hyperstomial, not closed by the operculum, broader than long (0.18 to 0.20 mm wide), prominent, smooth and imperforate when young but soon covered and embedded by the rough ectocyst and surrounding frontal walls. The species was described by Hastings from Gorgona, Colombia, and recorded also from Taboga, Jicaron and Coiba Islands, off Panama, and from the Galapagos Islands. Hancock Stations: recorded from more than 30 stations, all the way from southern California to the Galapagos Islands; Santa Cruz, Santa Rosa and Santa Catalina Islands and off the San Pedro break- water, southern California; Angel de la Guardia Island, Gulf of Cali- fornia; west coast of Mexico; Socorro Island; Costa Rica; Panama; Colombia ; Ecuador; and Wenman, James, Albemarle and Hood Islands, Galapagos. The known geographic range is from about 34°N to a little south of the equator, and the depth range from shore to 82 fms. 350 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Hippoporella hippopus (Smitt), 1867 Plate 45, figs. 8-9 Lepralia hippopus Smitt, 1867 :20. Lepralia hippopus, Hincks, 1880 :309. Lepraliella hippopus, Levinsen, 1916 :466. Hippoponella hippopus, Osburn, 1933 :44. The zoarium is encrusting on stones and shells, vitreous or white and glistening. The aperture is round anteriorly, nearly straight on the sides, the proximal border only slightly arcuate; 0.15 mm long by 0.12 mm wide; the strong cardelles are set far back and the shallow poster is about as broad as the anter. The vestibular arch smooth or delicately beaded. The operculum fills the aperture, well chitinized and yellow in color, indented on the sides at the position of the cardelles, and with a slightly sinuous sclerite separated from the border. The peristome is low and thin, with 2 to 4 small spines which soon disappear. The avicularia are round or ovate and vary in size, usually small, often one is found situated at one side of the median line and proximal to the aperture; others may apparently occur at any other position on the front. The ovicell is hyperstomial, not closed by the operculum, hemi- spherical, imperforate and smooth; it soon becomes more or less com- pletely immersed. This species has a slightly longer aperture and a smoother frontal than our other species; while the frontal becomes more coarsely granu- lated and irregular it never seems to develop the heavy tuberosities which are found on nitescens and gorgonensis. It has been recorded in Arctic waters from Spitsbergen to Greenland and the American Archipelago, and in the North Atlantic south to Great Britain and to Maine on the New England coast. Point Barrow, Alaska, Arctic Research Laboratory, 6 fms, common, G. E. MacGinitie, collector. Hippoporella nitescens (Hincks), 1884 Plate 45, figs. 4-5 Lepralia nitescens Hincks, 1883 : 450. Lepralia nitescens, O’Donoghue, 1923 :40. Hippoporella nitescens, Hastings, 1930: 724. The zoarium encrusts pebbles, shells, etc. The zooecia are of moderate size, 0.45 to 0.65 mm long by 0.40 to 0.50 mm wide, irregularly ovate, quincuncial, considerably inflated, distinct in younger stages. The frontal is a very thick vitreous or porcellanous pleurocyst, with a marginal row NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 351 of areolar pores and occasionally a few additional ones; when young the frontal may be slightly costate around the sides, but this is lost with increasing calcification, and frequently there is a low, rounded umbonate swelling on either side of the aperture. There is a thin shining ectocyst. The aperture is longer than broad, varying but averaging about 0.15 mm long by 0.13 mm wide, the sides nearly straight, the cardelles set far back, the poster very broad and shallow, the proximal margin nearly straight. The operculum fills the aperture, well chitinized and a sinuous sclerite runs forward from the cardelle on either side. The vestibular arch is delicately beaded. The peristome is low and thin, sometimes with 2 to 4 small spines which are lost very early, and the thick frontal sub- merges both aperture and peristome at the bottom of a deep tube. Proxi- mal to the aperture and a little to one side is a sofa avicularium (often wanting) with a semicircular mandible which is directed laterally; the chamber of the avicularium appears like an asymmetrical umbo and, with the thickening of the frontal it is often submerged to open into the secondary aperture. Similar small avicularia frequently appear else- where on the front. Dietellae are present. The ovicell has not hitherto been noticed. It is high, globular, imperforate and smooth but soon becomes covered by the pleurocyst of the adjoining zooecia; 0.26 mm wide. The species was described by Hincks from Houston Stewart Channel and Cumshewa, later listed by O’Donoghue from Northumberland Channel, British Columbia. Not taken in the Hancock dredgings, but collected at Middle Bank, Puget Sound, by Dr. John L. Mohr, several colonies. Hippoporella rimata new species Plate 45, figs. 6-7 Zoarium encrusting, white and shining. Zooecia small, 0.30 to 0.45 mm long by 0.25 to 0.30 mm wide, irregularly hexagonal; frontal thick, porcellanous, shining and with numerous comparatively large granules which are conspicuous even in the young. The aperture measures about 0.09 mm wide by 0.08 mm long, the anter rounded back to the prominent cardelles, behind which a very shallow poster extends the full width of the aperture with its proximal border straight or very slightly arched ; the vestibular arch is delicately beaded. The operculum is well chiti- nized, yellowish, with the sinuate sclerites separated from the. border. The peristome rises but little above the thick front, its rim provided with 4 or 5 short spines; notched on the proximal border to produce a 352 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 shallow secondary sinus. A suboral or labial avicularium is situated transversely above the aperture, a little to one side, the long-triangular mandible directed laterally; no other avicularia have been observed. Multilaminate colonies are nodular and the zooecia oriented in every direction. The ovicell is hyperstomial, prominent when young but becoming more or less embedded, inperforate; a striking feature is the large rima or fissure which extends nearly to the distal end of the ovicell and apparently never becomes closed. The small size and especially the widely cleft ovicell distinguish the species from any of its congeners. Type, AHF no. 70. Type locality, Hancock Station 155-34, Albemarle Island, Gala- pagos, 0°16’45”S, 91°22’52”W, 50 to 60 fms. Also at Station 170-34, Stephens Bay, Chatham Island, Galapagos, 32 fms; 210-34, Santa Elena Bay, Ecuador, near shore; and collected by Capt. Fred E. Lewis at Acapulco, Mexico, 15 fms. Genus AIMULOSIA Jullien, 1888 The frontal is a thick porcellanous pleurocyst with small areolar pores. The aperture is somewhat bell-shaped, widest at the proximal end; the poster extends the full width back of the cardelles, its border gently arcuate. The ovicell is hyperstomial, imperforate, not closed by the operculum, the orifice large, not much embedded. Avicularia, typi- cally median and suboral, but sometimes wanting in this position ; lateral- oral and frontal avicularia also often present. Oral spines and dietellae present. Genotype, Aimulosia australis Jullien, 1888 :59. Aimulosia uvulifera (Osburn), 1914 Plate 45, figs. 16-17 Lepralia uvulifera, Osburn, 1914:210; 1940 :427. Aimulosia uvulifera, Osborn, 1947:35. Zoarium encrusting, forming small white areas on shell fragments and corallines. The zooecia are small, about 0.25 to 30 mm long by 0.20 mm wide, distinct only when young; the frontal a thick porcel- lanous pleurocyst, highly arched and bearing a few areolar pores which are difficult to observe except in calcined specimens. The frontal rises into a high broad umbo which overhangs the aperture and often is trifid at the tip; frequently there is a much smaller pointed erect process on either side of the aperture, proximal to the oral spines. The aperture NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 353 is slightly longer than wide, about 0.10 by 0.08 mm, rounded distally, nearly straight on the sides and broadly arcuate on the proximal border (often nearly straight), the small cardelles set far back. The operculum has the form of the aperture, well chitinized, with a narrow sinuate sclerite running forward from the hinge inside from the border. The primary peristome is low and smooth and bears 6 slender spines which soon disappear; the frontal wall usually obscures the peristome. A minute pointed oral avicularium is sometimes present beneath the overhanging umbo; small frontal avicularia with a triangular mandible are scattered over the frontal area proximal to the aperture. The ovicell is hyperstomial, not closed by the operculum, prominent, broader than long and heavily calcified like the frontal; the orifice is comparatively wide and its upper edge is directed downward into a broad rounded labiate projection. Described from the Tortugas Islands, Florida, and later reported by Osburn from Porto Rico and the southern Caribbean Sea. Hancock Stations: 299, San Jose del Cabo, at the tip of the Lower California peninsula; 129-34, Braithwaite Bay, Socorro Island, west of Mexico; 116-33, Cocos Bay, 253-34, Port Culebra, and 328, Chatham Bay, Cocos Island, Costa Rica; 210-34, Santa Elena Bay, Ecuador; 173-34, South Seymour Island, Galapagos. Aimulosia palliolata (Canu and Bassler), 1928 Plate 42, figs. 9-11 Lepralia palliolata Canu and Bassler, 1928 :109. Zoaria small, white, encrusting shell fragments. The zooecia are distinct with deep separating grooves, ovate to elongate-hexagonal, 0.40 to 0.50 mm long by 0.25 to 0.35 mm wide. The frontal is a thick pleurocyst with one row of areolar pores, the surface smooth or with low irregularities: enclosing sides of the aperture and the suboral avicularium at a little distance is a high fold which is probably homol- ogous with the umbonal process of other species of the genus. The aperture is widest proximal to the cardelles, 0.10 mm long by 0.08 mm wide, the poster shallow and its border slightly concave. The operculum is well chitinized, a narrow sclerite extends straight across it between the cardelles and a very narrow sclerite close to the border bears the muscle attachments. The primary peristome is low and thin and bears 4 to 6 comparatively strong oral spines; the secondary peristome, formed by the frontal pleurocyst, rises into a high flaring wall which surrounds 354 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 the aperture and avicularium without obscuring them (rarely only a median umbo is present). he suboral avicularium is small with a triangular or semicircular mandible directed upward. The ovicell, 0.20 mm wide, is hyperstomial, not closed by the oper- culum, covered by a thick layer from the distal zooecium which often leaves exposed a small area of the endozooecium. I believe there can be no error in transferring this species to the genus Aimulosia. If the circumoral wall is merely an extension of the sides of the suboral umbo, all of the difficulties in interpretation disappear. Hitherto known only from the original record by Canu and Bassler, from the Straits of Florida. Hancock Station 143-34, off Wenman Island, Galapagos, 1923’10”N, 91°48’45”W, at 100 fms, several colonies (compared with specimens from Florida Straits); and 270, east coast of Angel de la Guardia Island, Gulf of California, 29°31’00’N, 113°27’00’W, at 10 fms. It is probable that the species extends all along the coast from the Gulf of California to the Galapagos Islands, since the colonies are very inconspicuous, Genus HIPPOPORIDRA Canu and Bassler, 1927 Hippotrema Canu and Bassler, 1927 :9. “The ovicell is hyperstomial and bears a frontal area. The zooecia are accumulated; the frontal is surrounded by areolar pores and often bears small avicularia. The aperture is formed of an anter and a poster separated by two cardelles. The large interzooecial avicularia are acuminated,’ Canu and Bassler, 1927:8. Genotype, Cellepora edax Busk, 1859. The frontal is a thick costulate pleurocyst with one or more rows of areolar pores. In the genotype, H. edax, there is usually a single row, but in H. calcarea, H. janthina and H. spiculifera there are some additional pores. The appearance of the last two species misled Canu and Bassler into erecting another genus, Hippotrema, on the supposition that the frontal is a tremocyst. The study of younger zooecia, however, reveals the fact that in all of the above species the formation of the frontal is identical, the pleurocyst arising from the margin and de- veloping centrally; when additional pores are present the openings of these are carried upward on the front and give the appearance of a tremocyst. In all other characters Hippotrema is similar to Hippoporidra and should be suppressed. NO. 2 OSBURN: EASTERN PACIFIC RBRYOZOA—CHEILOSTOMATA 305 Hippoporidra janthina (Smitt), 1873 Plate 45, figs. 13-15 Lepralia janthina Smitt, 1873 :63. Lepralia janthina, Osburn, 1914:213. Hippotrema janthina, Canu and Bassler, 1928 :141. Hippotrema janthina, Osburn, 1940 :454; 1947 :43. The zoarium usually encrusts gastropod shells, rising into rough prominences and subcylindrical branches, the ectocyst varying in color from white in the young to the deep violet color which is suggested in the name of the species. The zooecia are small, 0.30 to 0.40 mm long in the procumbent marginal ones. The frontal is a thick pleurocyst with large areolar pores and usually with a second row of pores; the pleurocyst arises as a series of costal ridges between the areolar pores and spreads upward to the aperture, carrying the openings of the pores upward at the same time, which often gives the frontal the appearance of a tremocyst; the ridges unite proximal to the aperture to form an irregular umbonate process. The aperture is a little elongate, about 0.11 by 0.09 mm, the anter rounded back to the strong cardelles between which the poster extends in a broad arch; the row of areolar pores extends around the distal end of the aperture. The primary peristome is low, thin and smooth, without spines; in advanced calcification the frontal may cover the primary peristome with a rough, slightly raised wall on which pointed tubercles are occasionally present. The oper- culum has the form of the aperture, indented on each side at the level of the cardelles, well chitinized and yellowish in color. Small pointed avicularia, much elevated, are usually present on the front, and rarely there are larger interzooecial avicularia with a longer mandible. The ovicells are prominent at first, not closed by the operculum, with a rounded frontal area which may become covered by secondary calcification. The species is common in the Gulf of Mexico, where it was described by Smitt and where it has been recorded by Osburn and by Canu and Bassler. It has not hitherto been noted on the Pacific coast. Hancock Stations: 1071-40, San Felipe Bay; 1078-40, Tepoca Bay ; 283, San Pedro Nolasco Island; and one colony (without other data) from Conception Bay, all from the Gulf of California between 26° and 31° N. Lat., at 2 to 60 fms; also 2196, at Cabeza Ballena, near the extreme tip of the peninsula of Lower California, 30 fms. 356 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Hippoporidra spiculifera (Canu and Bassler), 1930 Plate 55, figs. 8-10 Hippotrema spiculifera Canu and Bassler, 1930 :43. Zoarium encrusting and nodulous or erect with stout short branches. The zooecia are cumulate, not oriented except at the margins of encrust- ing colonies, more or less erected, little distinct, small, 0.25 to 0.40 mm long by 0.25 to 0.35 mm wide. The frontal area is ovate to hexagonal, thick and porcellanous, rising slightly to the aperture which, in the secondary layers often is nearly central; one or two rows of areolar pores. The aperture is slightly elongate, 0.12 mm long by 0.10 mm wide, straight on the sides, the small cardelles set far back and the poster broadly arched the full width of the aperture. The operculum has the form of the aperture, notched on the sides at the cardelles, well chitinized and yellow in color, with a narrow sclerite paralleling the margin. The full development this species presents an extravagant display of oral spines and spiny frontal processes. The peristome bears six tall slender spines, sometimes nearly as long as the zooecium. In the position of a central umbo is a tall pointed spinous process which is finely granulated to its tip, around the sides of the aperture and some- times elsewhere on the frontal are other similar sharp-pointed tall processes, and even on the top of the ovicell there may be one or two; occasionally these processes are bifurcated near the tip. Small sharp-pointed avicularia are frontal in position and turned in every direction. The ovicell is hyperstomial, prominent and smooth when young with a rounded area above the orifice, but later the whole wall becomes very thick and often bears a tall spine on the top. The species was described from Albatross Station 2813, Galapagos Islands at 40 fms. Hancock Stations, 137-34, Clarion Island, 18°19’05”N, 114°45/ 25’°W, at 57 fms; and 1078-40, and Tepoca Bay, Sonora Mexico, 30°14’57"N, 112°52’27”W, at 12 fms. Also in the Galtsoff collection from the Gulf of Panama, on pearl oyster shells. Also Barra Navidad, Jalisco, Mexico, low tide, Dr. Yale Dawson, collector. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 357 Hippoporidra granulosa Canu and Bassler, 1929 Plate 42, figs. 12-14 Zoarium encrusting shells. Zooecia of the primary layer recumbent and oriented, those of the secondary layers more or less erect and irregu- lar, the surface roughened. The frontal is imperforate except for a row of areolar pores, with rarely a few others; these pores are not carried up around the base of the peristome in secondary calcification. The frontal is coarsely granular even in the young stage and becomes excessively thick, as thick as the cavity beneath it, the areolar pores outlining the margin. The peristome is somewhat elevated in young zooecia and bears six small spines which soon disappear, and the thickening of the frontal soon obscures all evidence of the primary peristome. The secondary aperture is oval and somewhat expanded. The primary aperture is elongate, 0.14 by 0.10 mm, with strong car- delles, proximal to which the semicircular sinus measures about 0.07 mm across. The operculum is deeply incised on the sides at the point of attach- ment and bears a strongly sinuated sclerite on each side well removed from the margin. There are small frontal avicularia which appear to have no special relation to the aperture. The ovicells are small, opening well above the primary aperture and apparently have a small rounded frontal area, but in our specimen they are so deeply embedded in the thick crust that details cannot be determined. The species was described by Canu and Bassler from the Galapagos Islands, Albatross Sta. D.2813. Hancock Stations: 1049-40, Angel de la Guardia Island, Gulf of California, 29°32’47”N, 113°34’35’W, 54 fms, one colony, and 438, Chatham Island, Galapagos, 32 fms, one colony. Genus GEMELLIPORINA Bassler, 1936 “Proposed for species with keyhole-like aperture, hyperstomial ovi- cell and tremocystal frontal, with Gemellipora glabra Smitt, 1873, a common species in the Gulf of Mexico, as the type” (Bassler, 1936:161). The frontal is not a tremocyst, however, as young zooecia at the growing edge definitely show the development of a pleurocyst with one or two rows of areolar pores. On the very thick front of older zooecia these pores are more or less dispersed, giving an appearance somewhat like a tremocyst. The genotype has an erect zoarium with dichotomous 358 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 cylindrical branches; zooecia indistinct except at the growing edge; frontal wall very thick with tubular pores; distal part of zooecium raised, with stout oral spines; ovicell globular but soon covered by the distal pleurocyst except for a median cicatrix. Gemelliporina monilia new species Plate 41, fig. 13 Zoarium uniserial, encrusting on the rough surface of a small pebble, sparsely branched dichotomously. Zooecia small, 0.35 to 0.40 mm long by 0.25 mm wide, the base sometimes expanded to 0.30 mm; the proximal end only slightly narrowed. The frontal is a pleurocyst with small areolar pores; ventricose and the sides sloping downward to the dorsal side which is more or less expanded for attachment. Proximal to the aperture is a high arcuate umbonate process of varying size, sometimes not wider than the aperture, sometimes forming a high border around the sides of the aperture at a little distance from the peristome. he aperture is elongate, key-hole shaped, almost exactly like that of G. glabra (Smitt) the genotype; 0.13 mm long by 0.08 mm wide, the anter ellipsoid and the poster much smaller, resembling a deep sinus. The resemblance to glabra is further enhanced by the presence of six oral spines. The peristome is low and thin and is not encroached on by the thickening of the frontal. The operculum has the form of the aperture, moderately chitinized, with a narrow sclerite extending forward from the point of attachment somewhat within the border. The spines are peculiar in that there is a regular gradation in size, the proximal one on each side being tall and strong, the next one only about half as large and the third quite diminutive. The primary ooecium is globular, hyperstomial, smooth, imperforate and not closed by the operculum; secondarily a thick fold of the frontal of the distal zooecium partly covers it. The specimen is very small, with only 12 zooecia, three of which are ovicelled. The ancestrula is similar to the later zooecia except that it is much smaller; it gives off a string of zooecia from each end, one of which shows the base of a branch. Type, AHF no. 71. Type locality, Hancock Station 270, Angel de la Guardia Island, Gulf of California, 29°29’00”N, 113°27/00”W, 14 fms. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 359 Genus GEMELLIPORELLA Canu and Bassler, 1920 The ovicell is perforated, hyperstomial, and not closed by the oper- culum. The form of the aperture is like a keyhole. The frontal is a granular pleurocyst, with areolar pores. Avicularia are present near the aperture. Genotype, Gemelliporella vorax Canu and Bassler, 1923:111. This genus is much like Hippoporina in the form of the aperture and the nature of the frontal, but it has a finely perforated ovicell. Gemelliporella globulifera new species Plate 41, figs. 9-12 The zoarium is encrusting, usually on shells, white or pale yellow. Zooecia moderately small, 0.30 to 0.40, rarely as much as 0.50 mm long, by 0.25 to 0.35 mm wide (occasionally wider when the avicularium is large) ; inflated and distinct when young. The frontal is a thick, evenly granulated olocyst (? pleurocyst), with a very few areolar pores. The aperture is elongate, 0.13 to 0.16 mm long by 0.10 to 0.12 mm wide, the anter somewhat pyriform, the cardelles sharp and directed backward, the poster semicircular and one-half to two-thirds as wide as the anter; the peristome low and thin, not covered by the bordering frontal. The operculum has the form of the aperture, yellowish and well chitinized, with a thickered marginal sclerite. The avicularia are situated at the side of the aperture, frequently paired, the mandible semicircular to short-spatulate, rarely long-spatulate, varying much in size, the larger ones distorting the form of the zooecium, the chamber little elevated. The ovicell is unusually prominent, globular, 0.18 to 0.22 mm in width, perforated by numerous small pores; not closed by the operculum. The species appears to be much like Hippoporina fallax Canu and Bassler (1930:320) from the Philippines, which may possibly belong to this genus, but the poster of the aperture is larger, the operculum lacks the inner sclerite, the ovicell is coarsely granulated instead of smooth, and the avicularia different. Type, AHF no. 72. Type locality, Hancock Station 1303-41, one-half mile N of Platt Point, Santa Cruz Island, southern California, 34°03’50”N, 119°45/ 25’W, 36 fms, several colonies. Also taken at Station 1251-41, the San Benito Islands, Lower California, 28°12’35’”N, 115°34’35”'W, at 79 fms; off the San Pedro Breakwater at 20 fms, and Cortez Bank on the Mexican Border at 32 fms. Also from the Pleistocene of Newport Harbor, California, G. P. Kanakoff, collector. 360 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Gemelliporella aviculifera new species Plate 55, fig. 13 The zoarium is encrusting on small shell fragments and stems, the colonies all small. Zooecia small, 0.35 to 0.40 mm long by 0.30 to 0.35 mm wide, often somewhat accumulated, distinct when young. The frontal is a granulated pleurocyst with a few areolar pores which are dificult to observe except when calcined. The aperture is elongate, about 0.11 mm long by 0.09 mm wide, the poster noticeably wider than in G. globulifera, and the condyles less prominent. The operculum has the form of the aperture, slightly notched at the position of the cardelles, well chitinized with a bordering sclerite and yellow in color, the muscle attachments at the border. The peristome is low, thin and smooth, usually not obscured by the encroachment of the frontal. The most striking feature of the species is the large avicularium the base of which occupies a considerable portion of the frontal. It is situated near the aperture, at one side and proximal; it is much elevated and more or less pedunculate, broader at the top which is extended into a horizontal beak; the mandible long and narrow and strongly decurved, as much as 0.15 to 0.20 mm in length, hinged to a cross-bar. The avicularia are present on every zooecium and give a very rough appearance to the zoarial surface. The ovicell is globular, very prominent, not closed by the oper- culum, perforated by numerous small pores, 0.20 mm wide. The ovi- cells are usually very abundant, and in living specimens the frontal is almost entirely obscured by the large ovicells and avicularia but on dead colonies usually only the bases of these remain. Type, AHF no. 73. Type locality, Hancock Station 1245, 114 mi. southwest of Gull Island, off Santa Cruz Island, southern California, 33°56’00”N, 119° 5055” W, at 48 fms. Also 1294, Santa Cruz Island, and 232, 1050 and 1413-41 off San Miguel Island, southern California; 1250-41, San Benito Islands, Lower California, 28°18’15’N Lat., the most southern record. Depth range 10 to 44 fms. Gemelliporella inflata new species Plate 43, fig. 11 Zoarium encrusting, white. The zooecia are very distinct with a highly arched frontal and deep separating grooves, 0.55 to 0.70 mm long by 0.40 to 0.50 mm wide, ovate to elongate hexagonal in form and arranged in quincunx. The frontal is a rather thin pleurocyst, minutely NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 361 granular, with one row of small areolar pores. The aperture is elongate, 0.16 mm long by 0.12 or 0.13 mm wide, pyriform, the anter rounded back to the strong cardelles which are directed somewhat proximally, the poster is semicircular or slightly v-shaped and about two-thirds as wide as the anter. The peristome is thin, slightly elevated on the sides but entirely wanting proximal to the cardelles. Close behind the aperture and at one side is a conspicuous avicularium with a slightly elevated chamber and a long narrow rostrum directed proximally, the mandible (wanting in our specimen) attached by small hinge denticles. The ancestrula is small in comparison, 0.30 mm long by 0.16 mm wide, but is similar in most other respects to the later zooecia, even to the presence of an avicularium; the aperture differs in the poster which is comparatively broader and shallower. Ovicells wanting and the chitinous structures missing from our dead specimen. Some doubt remains as to the generic position, in the absence of the ovicell and operculum, and it may prove to be a Hippoporina. The larger size, thinner frontal wall and especially the nature of the avicularium sufficiently distinguish it as a species from any of our species of either Gemelliporella or Hippoporina. Type, AHF no. 74. Type locality, Hancock Station 1050, off San Miguel Island, south- ern California, at 34 fms, one colony about 1 cm in width. Genus LACERNA Jullien, 1888 The frontal is a pleurocyst with numerous areolar pores. The aperture is rounded, the proximal border with a deep narrow sinus; a narrow vestibular arch is present. Avicularia near the aperture, suboral or lateral. Peristome complete, with stout oral spines. Ovicell hyper- stomial, hemispherical, not closed by the operculum except in the passage of eggs; perforated, the pores varying in size. Genotype, Lacerna hosteensis Jullien, 1888 :48. In young zooecia the frontal is a veined olocyst which later is covered by a pleurocyst which may be either smooth or granular. The sinus is always a distinct median notch which varies from square to round and partially enclosed in different species. 362 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Lacerna fistulata (O’Donoghue), 1923 Plate 36, figs. 8-11 Schizoporella fistulata O’Donoghue, 1923 :37. The zoarium is encrusting, thin, white and glistening. The zooecia vary much in size and form, 0.40 to 0.65 mm long by 0.30 to 0.50 mm wide, often wider than long, irregularly quadrilateral or hexagonal, little inflated, distinct. The frontal is a veined olocyst in the young zooecium but this becomes covered by a comparatively thin pleurocyst which, in complete calcification, is slightly granular. There is a single row of areolar pores, with the addition of 1 or 2 more opposite the peristome. The aperture appears small in comparison with the zooecia, 0.10 mm wide by 0.08 long (not including the sinus) ; the proximal border nearly straight with a moderately deep and narrow rounded sinus; the vestibular arch is narrow. The operculum is moderately chitinized, with a narrow border and a narrow sclerite which parallels the border at a little distance. The peristome is thin, little elevated, bears about 6 oral spines and is united proximally with the avicularian chamber. The latter is small and narrow, shaped like a truncated cone, much elevated and curved forward above the sinus; the small avicularian mandible is triangular, situated on the distal side of the cone and directed upward; the chamber is bilaterally connected by a minute tube with the inner pores opposite the sinus and does not reach the marginal pores; rarely the chamber is slightly asymmetrical, in which case it is con- nected with only one of the pores. The ovicell is hyperstomial, very prominent, the distal end elevated, a little flattened on the frontal surface, perforated with pores of various sizes which are slightly collared; with advancing calcification the pleurocyst of the distal zooecium rises about the sides of the ovicell, covering nearly all of the perforated area and forming a small pointed umbo toward the distal end. The ovicell is longer than broad, 0.25 mm long by 0.22 mm wide, and often extends forward to the avicularian chamber of the distal zooecium. Described by O’Donoghue from Departure Bay, British Columbia, 15 fms. Our material agrees closely with the description, except that oral avicularian mandible is usually more or less pointed. Hancock Station 1191, Cortez Bank, 32°25’50”N, 119°07’30”W, at 32 fms. Also dredged at stations 1294-41, off Santa Cruz Island; 1289-41, off Santa Rosa Island, 47 fms; 1064, off Santa Barbara Island, and 1232-41, off the San Pedro Breakwater, southern Cali- fornia, 15 fms. Also found on a sunken buoy off Rocky Point, south- ern California, at 45 fms (Earl Fox, collector). NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 363 Genus HIPPOTHYRIS, new genus The frontal is a pleurocyst with several rows of pores and a com- paratively small imperforate central area; aperture with the anter semi- circular and the poster wide and shallow, the proximal border nearly straight, cardelles moderate in size; peristome thin and somewhat elevated, without spines, enclosing on the proximal border a small median avicularium. Ovicell globular, recumbent and not embedded, per- forated, not closed by the operculum. Genotype, Hippothyris emplastra new species. Hippothyris emplastra new species Plate 40, figs. 13-14 The zoarium forms a thin encrustation on siliceous sponges. The zooecia are large, 0.80 to 1.20 mm long by 0.65 to 0.90 mm wide, ovate, hexagonal or quadrate in form, very distinct. The frontal is a granulated pleurocyst with several rows of pores and a comparatively small imperforate central area which is delicately reticulate resembling a small breast-plate; the imperforate area is about as wide as the per- forated area on each side. The aperture is subquadrangular, the sides parallel, the poster about as wide as the anter and very shallow with the proximal border nearly straight; condyles moderate; broader than long, 0.18 to 0.20 mm wide by 0.14 to 0.16 mm long. The peristome is thin, a little elevated and on the proximal border encloses a small median avicularium with its short-triangular mandible directed vertically. The avicularian chamber is very small and umbonate in form. Spines want- ing. Multiporous septulae present. The ovicell is hyperstomial, globular and prominent, recumbent on the distal zooecium but not embedded, perforated and the rather large pores slightly collared; width about 0.35 mm but appearing small in comparison with the large zooecia. Type, U. S. Nat. Mus., 11029; paratype AHF no. 75. Type locality, Albatross Station D.5682, Magdalena Bay, on the west coast of Lower California, at 491 fms. Two colonies encrusting a siliceous sponge. Genus HIPPOMENELLA Canu and Bassler, 1917 “Hippoporininae with a finely perforate hyperstomial ovicell. Ori- fice with a shallow but wide poster separated from the anter by promi- nent condyles. Frontal avicularia generally paired forming prominent 364 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 chambers on either side of the median line near the orifice, the mandibles directed outward. Other subsidiary avicularia may be present. Frontal wall usually with a central smooth imperforate area, often greatly reduced, surrounded by concentric rows of irregular tube-like pores” (Brown, 1949:517). Genotype Lepralia mucronelliformis Waters, 1899. The description of the genus, as originally drawn by Canu and Bassler, is incorrect in a number of points and was evidently compiled from a number of species, some of which must belong elsewhere. Brown has carefully restudied type material of mucronelliformis and found the ovicell, which was overlooked by Waters; it is merely recumbent and not embedded, perforated and is definitely closed by the operculum, per- fectly plain without the lunar crescents described by Canu and Bassler. Hippomenella flava new species Plate 43, figs. 7-9 Zoarium encrusting, small, yellowish. Zooecia rather regular in arrangement, little inflated, separated by distinct grooves; moderate in size, 0.55 (0.45 to 0.70) mm long by about 0.40 mm wide, but some- times broader than long. ‘The frontal is a smooth pleurocyst when young and later bears low smooth ridges and bosses but there is no trace of an umbo; a row of moderately large areolar pores (often with 2 rows or even 3 toward the distal end) ; the inner pores carried upward on the imperforate central area in advanced calcification. The aperture is longer than wide (0.15 by 0.12 mm), rounded distally, nearly straight on the sides, with strong cardelles proximal to which is a wide shallow poster; the poster has a wide shallow sinus (?) of varying form, often wanting. The operculum does not conform to the proximal “sinus” but is nearly transverse on its proximal border; well chitinized, yellow, with a broad sclerite well within from the border. The peristome is thin, smooth, wanting on the proximal border, and bears about 6 slender spines. The avicularia are long-pointed, located at one or both sides of the proximal end of the aperture, or sometimes more proximally, directed outward and backward; the mandible very slender, varying in length from 0.20 to 0.50 mm, with a complete pivot bar. The ovicell is globose, closed by the operculum, smooth and shining, marginated around the base, perforated by numerous small pores; 0.30 mm wide, and the first oral spine on each side is not covered by the ovicell. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 365 Type, AHF no. 76. Type locality, Hancock Station 1340-41, Tanner Bank, off San Diego, California, 32°41/00”N, 119°06’30”W, at 38 fms. Also at Station 1896-49, Tanner Bank, 22 fms; and 1196, Cortez Bank, 32° 35/00”N, 119°11’45”W, at 110 fms. Genus HIPPOMONAVELLA Bassler, 1934 “The ovicell is hyperstomial. The frontal is a pleurocyst surrounded by a row of areolar pores. he aperture bears two cardelles more or less median. In front of the aperture there is an oral avicularium placed on the median axis of the zooecium. Genotype, Lepralia praeclara Mac- Gillivray, 1895.” Bassler, 1934:407. It should be added that the ovicell is closed by the operculum, and that more often than not the avicularium is off center and frequently at the side of the aperture with all intermediate positions represented. The operculum is well chitinized, yellowish in color. Apparently the genus has not been recognized except as a fossil, but two living species, Schizoporella longirostrata Hincks, 1883, and Hippo- menella parvicapitata Canu and Bassler, 1930, are modern representa- tives. Hippomonavella longirostrata (Hincks), 1883 Plate 43, figs. 1-3 Schizoporella longirostrata Hincks, 1883 :477. Schizoporella longirostrata, Robertson, 1908:291. Schizoporella longirostrata, O’Donoghue, 1923 :36. Schizomavella longirostrata, Canu and Bassler, 1923:109. Schizomavella longirostrata, O’ Donoghue, 1925 :102; 1926:59. Zoarium encrusting on shells and stems, the thick ectocyst gray or light brown. Zooecia moderate in size, 0.45 to 0.65 mm long by 0.30 to 0.40 mm wide, distinct, slightly inflated, rather regularly arranged in radiating lines. The frontal is a granular pleurocyst with a row of areolar pores and usually with 2 or 3 additional rows; sometimes most of the frontal is perforated, but the central area is always imperforate. The primary aperture (about 0.15 mm in either dimension) is rounded distally, straight on the sides, and the poster extends the full width behind the strong cardelles with a broad shallow sinus; as pointed out in Hincks’ original description, there is considerable variation in the form of the poster. The operculum is well chitinzed, light brown in 366 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 color, with a narrow sinuous sclerite slightly within from the border. The peristome is thin and low, raised only on the sides into low lappets. There are 5 to 7 slender oral spines which are soon lost. The avicularia are elongate, sharp pointed and quite variable in size and arrangement (length 0.13 to 0.30 mm) ; typically they are located just proximal to and at one side of the aperture and are directed toward the proximal end of the zooecium; sometimes they are nearly median, again they may be situated at the side of the aperture and directed out- ward, and rarely they are paired, one on each side of the aperture. All of these variations may be found in the same colony. The ovicell is prominent, hemispherical or slightly elongate, 0.24 to 0.28 mm wide, perforated and closed by the operculum. The granular pleurocystal frontal, the nature of the avicularia and their occasional position similar to that in the genotype, the closure of the ovicell and the characters of the aperture and operculum all appear to ally this species to Hippomonavella. Described by Hincks from Virago Sound and Cumshewa Harbor, British Columbia; listed by Robertson from southern California; by O’Donoghue from numerous localities in Puget Sound and British Columbia, and by Canu and Bassler from the Pleistocene of Santa Barbara, California. Hancock Stations: 18 stations about the islands off southern Cali- fornia; 3 stations off Cedros Island, Lower California, and 2 stations (1045-40 and 1050-40) off Tiburon Island and Angel de la Guardia Island, in the upper part of the Gulf of California. The geographical range appears to be from British Columbia to about 28° N Lat., and the bathymetric range from shallow water to 100 fms. Hippomonavella parvicapitata (Canu and Bassler), 1930 Plate 43, figs. 4-6 Hippomenella parvicapitata Canu and Bassler, 1930 :19. Zoaria encrusting, sometimes multilaminar. ‘The zooecia are of moderate size, 0.55 to 0.70 mm long by 0.40 to 0.50 mm wide, some- what ventricose and separated by deep grooves, elliptical or long hexag- onal. The frontal is a granular pleurocyst, sometimes with a low umbo, surrounded by one or two rows (more rarely 3) of areolar pores. The primary aperture is semielliptical, 0.14 mm wide by 0.16 mm long, often narrowed slightly toward the proximal end, the proximal border broadly arcuate between the small cardelles. The peristome is thin and slightly elevated all around the aperture, with about six small oral NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 367 spines which soon disappear. The operculum is well chitinized, yellow, with a broad, lateral sclerite which divides beyond the muscle attach- ments, one band continuing distally around the margin while a much narrower branch continues at some distance within from the border. The avicularia are long-pointed, often paired and located usually at the sides of the aperture about opposite the cardelles and directed more or less laterally and backward; not infrequently they are single and more proximally located, occasionally median or nearly so and directed back- ward; the mandible may be as much as 0.30 mm long but usually is much shorter; attached by an incomplete pivot. The ovicell is hyperstomial, closed by the operculum, hemispherical and prominent, with numerous small pores, somewhat marginated around the base. Described by Canu and Bassler from the Galapagos Islands. Hancock Stations: 143-34, Wenman Island, Galapagos, 100-150 fms; 239-34, Port Utria, Colombia, shore collection; 431-35, Octavia Rocks, Colombia, 45 fms; and 275, Raza Island, Gulf of California, 28°48’00”N, 113°00’00”W, at 40 fms. Genus STEPHANOSELLA Canu and Bassler, 1917 Buffonellaria Canu and Bassler, 1927. “The ovicell is hyperstomial and embedded in the distal zooecia. It opens above the apertura by an especial orifice. The frontal is a smooth olocyst. No spines. The ovicelled zooecia have a large apertura and their avicularium is frontal.’’ (Canu and Bassler, 1917:40). Genotype, Eschara biaperta Michelin. Later (1930:16-17) Canu and Bassler withdrew the genus and re- ferred biaperta to Schizopodrella because of the “tremocystal” frontal. “Our genus Stephanosella has no further reason for existence and should be suppressed.” Still later Bassler (1935:207) returned to the use of Stephanosella. The confusion arose when Smitt (1873:46) and Hincks (1880: 255) combined with biaperta Michelin another species which has a similar ovicell but a tremocystal frontal. Busk (1859:47, ? Lepralia biaperta) correctly interpreted the species and Smitt in his, earlier work (1867:14) also figured his Escharella linearis forma biaperta correctly with areolar pores only. Also Nordgaard (1906:15-16) had the true biaperta. 368 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 The original description of Stephanosella, as given above, needs only a few comments. The frontal is smooth in the young but becomes ir- regularly roughened with age; the ovicell at first is prominent but becomes covered by the excessively thick frontal wall except for a small sculptured area on the top; the aperture of the ovicelled zooecia differs very little in size from the others. The genus Buffonellaria Canu and Bassler, 1927, presents no funda- mental differences and is a pure synonym; the genotype, Hippothoa divergens Smitt, is merely a thinner-walled and smoother Stephanosella. Dr. Bassler (in litt.) agrees to this synonymy. Stephanosella biaperta (Michelin), 1845 Plate 42, figs. 1-2 Eschara biaperta Michelin, 1845 :330. Lepralia biaperta, Busk, 1859 :47. Escharella linearis forma biaperta, Smitt, 1867 :14. Schizoporella biaperta, Nordgaard, 1906:15. Not Hippothoa biaperta, Smitt, 1873:46. Schizoporella biaperta, Hincks, 1880:255 (in part). Not Schizoporella biaperta, Osburn, 1912 :237. Not Stephanellosa (sic) biaperta, Canu and Bassler, 1925 :30. Schizoporella biaperta, Robertson, 1908:287 (in part). Not Stephanosella biaperta, Canu and Bassler, 1923 :99. Zoarium encrusting, sometimes multilaminate and forming rough colonies. Zooecia moderate in size, 0.55 to 0.70 mm long by 0.35 to 0.50 mm wide, ovate to roughly hexagonal in form, slightly inflated and distinct when young. The frontal is an olocyst, smooth and veined in the young but becoming very thick and somewhat roughened; a row of 4 or 5 areolar pores on each side, difficult to see except when calcined. Aperture a little broader than long, about 0.12 mm long by 0.15 wide, the proximal border with a shallow rounded sinus. The operculum has the form of the aperture, well chitinized, yellowish in color, the border with a narrow sclerite, a small lucida at the points of attachment and the muscle attachments well within from the border (in typical schizo- porellid fashion). The peristome is low and thin, without spines. The avicularia are of two kinds, (1) lateral-oral, usually paired on a small elevated chamber at the sides of the aperture, the mandible either rounded or pointed; (2) a larger frontal avicularium, considerably elevated with a pointed mandible, the chamber connected with one of the areolar pores. No. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 369 The ovicell is rounded and prominent at first but soon becomes deeply embedded in the thick crust of the distal zooecium, imperforate and radiately grooved. The secondary layer is incomplete, leaving a rounded area on the top which appears to have a peripheral row of pores, but the “pores’’ are merely the bottoms of the grooves at the edge of the covering layer. Width of ovicell about 0.26 mm. This species has evidently been confused with another of a different genus (see Schizoporella cornuta) which has the same type of ovicell and oral avicularia but in which the frontal is a tremocyst with numer- ous frontal pores. Described by Michelin and later recorded by Busk as a fossil. Known as a recent species from Spitsbergen to Greenland and south to the British Isles. Reported by Robertson from Alaska and by Hincks and by O’Donoghue from various localities in British Columbia, but these records are doubtful. That of Robertson from Alaska may be correct, but Hincks states that “The surface of the younger cells is thickly cov- ered with minute punctures,” which is not a character of Stephanosella. Not taken in the Hancock dredging but collected by MacGinitie at Point Barrow, Alaska, (Arctic Research Laboratory). It appears to be a circumpolar and northern species. Stephanosella vitrea new species Plate 42, figs. 6-8 Zoarium small, encrusting, especially on stems, worm tubes, etc., vitreous or porcellanous, the surface often rough. Zooecia small, 0.30 to 0.45 mm long by 0.25 to 0.35 mm wide, distinct only when very young. The frontal is a smooth vitreous olocyst which later becomes very thick and irregular, except for a small area around the aperture; a few small areolar pores and occasionally a few additional ones irreg- ularly situated; with the thickening of the olocyst the pores are some- times carried up on the front. The aperture, always clearly visible even in highly calcified specimens, varies slightly in dimensions but averages about 0.10 mm wide by 0.11 mm long, nearly round back to the car- delles, proximal to which is a v-shaped sinus; the sinus also varies some- what, occasionally almost slit-like. The peristone is low, smooth, without spines, and is not involved in the secondary thickening of the front. The operculum has the form of the aperture, moderately chitinized with a narrow, thickened border, the muscle attachments distant from the margin. There is a pair of small oral avicularia with a pointed (some- 370 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 times rounded) mandible opposite the sinus or a little proximal to it; these usually lie at the bottom of the circumoral depression, but may be more or less fused with the thick frontal. A larger avicularium occupies much of the frontal surface, its chamber elevated, the mandible variously directed and with a strong hinge bar. The ovicell is about 0.18 mm wide, globular, not closed by the operculum, imperforate, very prominent at first but later immersed more or less in the thick frontal of the distal zooecium which leaves in view only a radiately grooved rounded area on the top. This species resembles a miniature S. biaperta, but is much smaller in all measurements, the sinus narrower and more definitely v-shaped and the anter less transverse. Type, AHF no. 77. Type locality, Hancock Station 1388-41, off East Point of Santa Rosa Island, southern California, 33°54’30”N, 119°54’28”W, at 54 fms. Also at stations 1387-41, off Santa Rosa Island, 52 fms; 1067, N.E. of Santa Barbara Island, 83 fms, southern California; 1241 and 2160, S. of San Benito Islands, W. of Lower California, 44 fms; 2131, N. of Isla Partida, Gulf of California, 75 fms, and 438, Chatham Island, Galapagos. Other specimens in collection are from Banderas Bay, W. Mexico (about 21°30’N), and from Middle Bank, Puget Sound, Washington (about 48°30’N), Dr. J. L. Mohr, collector. The Pleistocene of Santa Barbara, California, also yielded a number of specimens, collected by Mr. J. D. Soule. Stephanosella bolini new species Plate 42, figs. 3-5 Zoarium encrusting the rough surfaces of pebbles, white and por- cellanous. Zooecia large, 0.70 to 0.90 mm long to 0.50 to 0.65 mm wide, very irregular in size, form and orientation; distinct in younger stages, little inflated. The frontal is a very thick olocyst with large areolar pores and a varying number of smaller ones irregularly dis- tributed over the proximal part of the front; the appearance is some- times very much like a tremocyst but there is no secondary frontal layer and the pores are always absent from an area proximal to the aperture. The surface is more or less irregular in older zooecia but there are no umbonate processes. The aperture is rounded back to the cardelles, and proximal to these has a shallow, broad, u-shaped sinus; about 0.17 mm in either dimension; the peristome is low and smooth, without spines and is usually obscured NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA s/t by the secondary peristome which forms a low, broad, smooth wall. The operculum is yellowish in color, with a complete narrow bordering sclerite and the muscle attachments situated well within from the border. Usually there are two pairs of lateral-oral avicularia; one pair very small, situated about opposite the middle of the aperture, a little elevated, close to the aperture and involved in the secondary peristome; a larger pair situated about opposite the sinus, farther removed from the aperture and embedded in the frontal wall; the mandibles of the smaller ones are directed backward, those of the larger ones laterally. Occasionally there are one or more additional avicularia, similar to the larger oral ones, situated along the zooecial margin. The ovicell is very prominent, hyperstomial, not closed by the oper- culum, the surface radiately grooved, and collared around the base, its width about 0.30 mm. The species is dedicated to Dr. Rolf L. Bolin of the Hopkins Marine Station, Pacific Grove, California, who has contributed much fine ma- terial for the present monograph. Type, AHF no. 78. Type locality, off Point Sur, California, 36°20’45”N, 121°06’15”W, at 208 fms, Bolin and Budd, collectors, several colonies. Also at Han- cock Station 1387-41, east of Santa Rosa Island, southern California, 33°54’05”N, 119°54’10”’W, at 52 fms. 3/2 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Family Exochellidae new family The frontal is a pleurocyst with radiating costae and a series of areolar pores; the aperture slants downward and forward and has no proximal sinus (rimule) and no cardelles; the well-chitinized operculum bears a bordering sclerite for attachment of the opercular muscles; avi- cularia are usually well developed, frequently paired opposite the aper- ture, and oral spines are well developed and sometimes jointed. Genus ESCHAROIDES Milne-Edwards, 1836 Peristomella Levinsen, 1902. The aperture is oblique, without lyrula, cardelles or rimule. Ovicell hyperstomial, embedded, opening above the primary aperture. The frontal is a pleurocyst, with areolar pores. A small mucro usually pro- jects into the secondary aperture from the proximal lip of the peristome. Avicularia are usually paired at the sides of the peristome, directed more or less laterally. Oral spines present. Genotype, Cellepora coccinea Abildgaard, 1805. Escharoides praestans (Hincks), 1882 Plate 43, fig. 12 Mucronella praestans Hincks, 1882 :168. A large attractive species, the zoarium unilaminar and encrusting on shells, corallines, etc., white and glistening when young. Zooecia robust, large, 0.90 (0.70 to 1.00) mm by 0.50 (0.45 to 0.60) mm, much elevated distally. The front is a pleurocyst with large, deep areolar pores in one or two rows, the pores often separated by strong ribs. “The peristome is much elevated on the proximal border, less so on the sides and very little distally, moderately thin. A denticle (“umbo’’), tri- angular, quadrate or short spatulate, situated high up on or just within the proximal tip of the peristome (similar in appearance to a lyrula but not homologous). The secondary aperture is large, about 0.20 by 0.20 mm, directed forward, rounded-pyriform in outline; on the distal border there are 4 large conspicuous spines jointed at the base. The primary aperture which, except in the very young, can be seen only after dissec- tion is rounded proximally, without cardelles, the distal border is nearly transverse often with a peculiar rounded lip projecting slightly inward and backward. The avicularia are paired or single at the sides of the aperture, varying in size and form from small and sharp-pointed to very NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 3/3 long and spatulate; the small ones are usually beside the aperture and directed forward, the large ones situated more proximally are directed laterally. The ovicell is hyperstomial, much immersed, costate like the frontal, with a central umbonate process. Recorded from New Zealand and Australia. Hancock Stations: 143-34, Wenman Island, shore; 155-34 and 455, Albemarle Island, 50 to 70 fms; 788-38, Daphne Major Island, 55 fms, all from the Galapagos. Also 271, Angel de la Guardia Island, Gulf of California, 29°31’00”N, 113°28’30’W, at 10 fms. These are the first records of this species from the American coasts and indicate a wide distribution. Genus TRYPEMATELLA Canu and Bassler, 1920 The ovicell is hyperstomial and closed by the operculum only for the passage of the eggs. The aperture is semilunar with proximal border a little concave. The frontal is a thick pleurocyst with large areolar pores. Two large lateral avicularia are placed below the aperture; also a small rounded avicularium on either side of the aperture. Genotype, Trype- matella papulifera, Canu and Bassler, 1923:135. Trypematella umbonula new species Plate 43, figs. 13-14 Zoarium encrusting on a shell, multilaminar, white, rough in ap- pearance. Zooecia of moderate size, 0.40 to 0.50 mm long by 0.30 to 0.40 mm wide; the frontal a thick pleurocyst with large areolar pores, occasional additional smaller pores, short costal ridges and irregulari- ties of surface, and a prominent suboral umbo. The primary aperture is wider than long, 0.12 by 0.10 mm, the proximal border broadly arcuate or with a broad shallow sinus and without cardelles; peristome low and thin, with 4 delicate spines which are seen only on marginal zooecia. The avicularia are distributed as follows: a small rounded one on each side of the aperture, another of similar size and form on the distal side of the suboral umbo, and more rarely a larger pointed one on the side of the zooecial front. The ovicell is moderately large, 0.20 to 0.25 mm wide and broader than long, prominent when young but becoming considerably embedded, somewhat flattened above the orifice, an ovate fenestra near the proximal 374 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 corner on each side and one or more smaller pores between these; in advanced calcification the base of the ovicell is bordered by a costate band and there is a small, centrally situated umbo on the top. The genotype, T. papulifera Canu and Bassler, was described from the Pleistocene of Rustic Canyon, Santa Monica, California. The present species, which may be its modern representative, agrees in all important details except for the presence of the suboral umbo and avi- cularium; the paired frontal avicularia of papulifera are represented rarely by a single one of the same form and position. As the genus has been known only as a fossil from the one locality mentioned above, it is especially interesting to find a recent representative in the same general region. Type, AHF no. 79. Type locality, west end of Santa Catalina Island, southern Cali- fornia; a single zoarium without further data, from the Los Angeles Museum. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 3/5 Family Microporellidae Hincks, 1880 The most important character is a small median pore, the ascopore, at a little distance proximal to the aperture. It is the outlet of the ascus or compensation sac, and varies in form and position in the different species, and it may also show considerable variation with different de- degrees of calcification. The aperture is nearly straight on the proximal border, and the operculum is simple, having no extension proximal to the cardelles. Spines are present on the peristome and avicularia are present in the genus Microporella. The frontal is a tremocyst. Dietellae present. The ovicell is hyperstomial and closed by the operculum. Genus MICROPORELLA Hincks 1877 The aperture is semicircular, straight on the proximal border. The ascopore is semilunar or round and is situated rather close to the aper- ture so that there are no tremopores between. Pointed avicularia are present in various positions. Genotype, Eschara ciliata Pallas, 1766. The question of what is a “good species’ rises again and again in this genus, as most of the differential characters are subject to variation. The avicularia differ in position, alongside or slightly distal to the asco- pore, or on the front proximal to it; in the latter case they are usually more lateral in position. There is some variation, however, in some of the species, as in ciliata where occasionally an avicularium may be found beside the ascopore. The number is of some importance, whether single or paired, but again those with a single avicularium may occasionally have two and those which ordinarily are paired may have only one. The form of the mandible also varies within the species, and species with long-triangular mandibles may have them more or less setose, even within the same colony. The form of the aperture varies in the different species from semicircular to considerably more than a semicircle, and the same colony may show some variation; also the proximal border may or may not bear small hinge teeth. The umbos in some are heavily developed, in others they are smaller and in still others they may be evident only occasionally. The ovicell offers little of importance, though in some forms it is developed around the aperture farther than in others, in some it bears a collar around the orifice, and in some cases the size is useful. The size and number of the spines have been made use of, but here the variation, especially in size, is very great. 376 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Still these forms are different and can be separated usually without much difficulty if the colonies are fully developed. Several of these species occur in the Pleistocene, where they present just the same char- acters shown by the recent specimens, e.g. californica, umbonata, and vibraculifera, while ciliata is known as far back as the Miocene. It appears evident that they are different and have been for a long time, even though they do not show as sharp distinctions as are often found in other genera. Fortunately most of them present more than one dis- tinguishing character and I have been able to present the following key which at least enables one to separate the forms named in the following pages. I have listed most of them as species, as otherwise it would seem necessary to regard all of them as varieties of ciliata. Key TO THE SPECIES OF Microporella 1. Avicularia single, occasionally paired, proximal to ascopore. . 2 Avicularia paired, occasionally single, beside the ascopore . . 6 2. Avicularium large with exceedingly long flagellum . vibraculifera Avicularium smaller, mandible usually ending in a setose point 3 3. Three umbos, 1 central, the others beside the aperture . wmbonata Oneumboornone ... . : : 2 os tae Sea 4. Aperture and ascopore Beer is a high Saar which is bridged across its middle in fertile zooecia . . . . pontifica The peristome not elevated . . . . P « S. ote es 5. Avicularium small, located in the feel a iettl angle, the mandible setose, directed somewhat laterally . . . gibbosula Avicularium larger, usually located on one side a little proximal to the ascopore, mandible long triangular to setose (the variety stellata with a stellate ascopore) . . . PE br 7! 6. Avicularia far forward beside aperture, aandibles setose, very long and directed forward parallel . . . . . . tractabilis Avicularia beside ascopore, mandible setose or lanceolate, not unusually long, directed diagonally forward . . . ... 7 7. Ascopore surrounded proximally by an arcuate umbo of vary- IN®SIZE Ss ie Hed a a Pens ee LTT Umbo, if present, caiieed Bh Be sas a Or 8. Mandible long-triangular, with a more or less setose point . . 9 Mandible setiform or long:hastate . . . . . . + « « se NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA StL 9. Ascopore large with cribrate aperture (sieve plate) . . cribrosa Ascopore with the usual lunate aperture . . . . . californica 10. Avicularia small, a small setose mandible . . . . . setiformis Avicularia with narrow hastate mandible ending in a setose ethic e al Poco. Bua) a nyop 8) - J ase, CONOR Microporella ciliata (Pallas), 1766 Plate 44, fig. 1 Eschara ciliata var. B Pallas, 1766:38. Cellepora ciliata, Linnaeus, 1759 :1286. Microporella ciliata, Hincks, 1880 :206; 1884:14. Microporella ciliata, O’ Donoghue, 1823 :31 ; 1925 :103 ; 1926 :64. Microporella ciliata, Canu and Bassler, 1923 :119. Microporella ciliata, Hastings, 1930 :727. Zoarium encrusting on various substrata, especially shells and stones. The zooecia are somewhat ovate to elongate hexagonal; (length 0.45 to 0.50, width 0.30) ; the front with numerous small tremopores, slightly inflated, smooth and usually without decoration, though a small median umbonate process is sometimes present. The aperture is nearly semi- circular, evenly rounded in front and on the sides and straight on the proximal border; 0.08 or 0.09 mm long by 0.11 to 0.13 mm wide; the peristome low and smooth with 5 to 7 oral spines. The ascopore, in the midline a little proximal to the aperture, is lunate (a small calcified shelf projects backward from the distal border of the pore partially closing the pore). The ovicell is globose and prominent, smooth or umbonated on the top and ribbed around the base; a slight collar around the aperture; about 0.25 mm in width. Usually there is a single avicularium situated a little to one side of the midline and proximal to the ascopore, the mandible long triangular to more or less setose directed forward and outward. Occasionally there are two avicularia symmetrically placed, and the location may vary from the lateral zooecial angle to opposite the ascopore. A cosmopolitan species, listed on the American Pacific coast by Hincks and O’Donoghue from British Columbia waters and by Hastings from Panama, Colombia and the Galapagos Islands. In the Hancock collections it appeared at nearly 100 stations from the coast of Oregon to the Galapagos Islands, from near shore to depth of 90 fathoms. 378 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Microporella ciliata stellata (Verrill), 1875 Porellina stellata Verrill, 1875 :53. Microporella ciliata var. stellata, Osburn, 1912 :234. Microporella ciliata var. stellata, O’ Donoghue, 1923 :30. Similar in all respects to M. ciliata except that the ascopore is not provided with a calcified shelf but with minute spicules all around the border which give the pore a stellate appearance. Occasionally a small shelf is present, similar to that of ciliata but smaller. Described by Verrill from Casco Bay, Maine, and found commonly by Osburn in the Woods Hole region of Massachusetts. O’ Donoghue records it from British Columbia. Hancock collections: specimens with the stellate pore and with inter- mediate conditions from Mussel Point, Dillon Beach and Monterey Bay, California. Microporella umbonata (Hincks), 1884 Plate 44, fig. 4 Microporella ciliata form umbonata Hincks, 1884:15. Microporella ciliata var. umbonata, O’ Donoghue, 1923 :31. Microporella umbonata, Canu and Bassler, 1923 :123. The general characters of this form are much like those of ciliata, but in its complete calcification it presents a very striking appearance with high pointed umbos on the front and the ovicell and on each side of the aperture. The zooecia are slightly larger than those of ciliata, very heavily calcified, the gibbous frontal comparatively smooth except for the median umbo, the tremopores large and numerous. The aper- ture is more elongate than in ciliata, forming more than a semicircle, the proximal border straight, cardelles not evident. The peristome is low and thin, with 4 to 6 small oral spines which are evanescent. The ascopore is of moderate size, semilunar, close to the border of the aper- ture and usually obscured by the median umbo. There is a single avicularium, often wanting, situated as in ciliata at one side proximal to the ascopore and oriented diagonally. The ovicell is large, 0.28 to 0.33 mm wide, heavily calcified, per- forated like the frontal, with a large blunt or pointed umbo on the top. The lateral umbos are usually tipped forward as in Hincks’ figure 1 (plate 17), but occasionally stand erect beside the aperture. Described by Hincks from Dolomite Narrows, British Columbia; listed by O’Donoghue without data, and recorded by Canu and Bassler NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 379 from the Pleistocene of Santa Barbara, Santa Monica and San Pedro, California. Hancock Stations: 1232-41, San Pedro, and 1300-41, Santa Cruz Island, California. Also from Dillon Beach, California (Menzies, collector). Shallow water to 56 fms. Microporella vibraculifera (Hincks), 1884 Plate 44, fig. 7 Microporella ciliata form vibraculifera Hincks, 1884:15. Microporella ciliata var. vibraculifera, O’ Donoghue, 1923 :31; 1926 :64. Microporella vibraculifera, Canu and Bassler, 1923 :124. There is much general resemblance of this species to ciliata, but it is larger in all dimensions, coarser in appearance, and the avicularium is strikingly different. The zoarium is encrusting on shells, stones and coarser algae. The zooecia are irregularly elongate hexagonal, 0.50 to 0.60 mm long by 0.34 to 0.40 mm wide, a little inflated, the frontal with large tremopores when the smooth shining ectocyst is removed. The aperture is semicircular with the proximal corners a little rounded, the proximal border straight and with no evidence of cardelles, 0.09 mm long by 0.13 mm wide. The peristome is thin, a little elevated and provided with 5 to 7 stout spines. The ascopore, as in ciliata, is reduced to a lunate slit by the development of the shelf on the proximal border; the rim of the pore is very slightly elevated. The avicularium, comparatively, is of giant proportions, its chamber usually extending laterally over more than half the width of the front and elevated on its proximal side so that it appears to be tipped forward; there is a very heavy pivot; the setose mandibles, which may be 1.00 mm or more in length, are grooved on the under surface for their entire length, with a pair of minute hooks near the base, and are directed more or less sideways. There is no difficulty in identifying the species when the mandibles are present and even when these are denuded the size and position of the avicularian base, with its unusually strong hinge bar, easily distinguish it. The ovicell is large, 0.35 to 0.40 mm wide, smooth or slightly umbonate, ribbed around the base and usually with a thick, raised collar around its aperture. Described by Hincks from British Columbia, “Queen Charlotte Islands,” and listed by O’Donoghue without special data. Canu and Bassler record it from the Pleistocene of San Pedro, Santa Monica and Santa Barbara, southern California. 380 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Hancock Stations: 1232-41, San Pedro; 1171-40, 1371-41 and 1118, off Santa Catalina Island; 1051, San Miguel Island, and 1153, Santa Rosa Island, all from southern California. Stations 488-36, San Quentin Bay; 1250-41, San Benito Island, and 1261-41, Dewey Channel, all from Lower California, west coast. 5 to 160 fms. Also at Middle Bank, Puget Sound, Washington, Dr. J. L. Mohr, collector. These records extend the range from British Columbia to about the parallel 28°N Lat. Microporella cribrosa new species Plate 44, fig. 3 Microporella californica Robertson, 1908 :281 (non Busk). There is much general zoarial resemblance to californica Busk, but differences occur in several characters. The most evident of these is the presence of a perforated cover, “sieve plate’ (Robertson), over the asco- pore, instead of the usual lunate opening. The zoarium usually encrusts algae, but sometimes is found on shells and pebbles. The zooecia resemble those of californica but average smaller, about 52 mm long by 0.35 mm wide. The tremopores are large and there is often a small umbonate process proximal to the ascopore: the process rarely becomes high and flabellate. The aperture is more transverse than usual in this genus, nearly twice as wide as long, 0.07 to 0.08 long by 0.13 to 0.15 mm wide, straight on the proximal border, the small cardelles usually evident. The ascopore is larger than in any other of our species, transversely short-elliptical, often a little inflected on the distal border where a small projection may extend a short distance into the aperture; the remainder of the aperture of the ascopore is filled in with a calcified, porous mem- brane, the numerous pores perfectly round (Robertson’s figure represents this feature well). The avicularia are similar in form and position to those of cali- fornica but smaller. The spines, usually 6 (5 to 7), are long, sometimes longer than a zooecium, and strong, jointed at the base and occasionally dark about the basal joint. The ovicells are larger than those of californica (though the zooecia are smaller), averaging 0.35 mm in width (0.33 to 0.38 mm), the base of young undeveloped ones measuring 0.28 mm in width. As in most species of the genus they are ribbed about the base, but the base is rather sharply constricted. A low smooth umbo is present on the top and the sides extend backward to the proximal spines. No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 381 The characters mentioned appear only slight for the separation of a new species but the cribrate covering of the ascopore is very definite and I have not been able to find any evidence of intergradation with the usual form of ascopore in other species. Spinules are present in several other species, both on the distal projection and around the inner border, but they never appear to fuse to form rounded pores over the whole area as they do in cribrosa. The smaller zooecia with larger and less embedded ovicells also separate it from californica. It should be noted that in dead specimens with the ectocyst removed, the cribroid plate is usually lost and the ascopore resembles that of californica except that it is much larger. Type, AHF no. 80. Type locality, Corona del Mar, Newport Harbor, southern Cali- fornia, growing on algae attached to the piles of docks. Occurring com- monly along shore from Mussel Point, northern California (A. E. Blagg, collector) southward to Tomales Bay, Monterey Bay, Santa Barbara, San Pedro Harbor, Newport Harbor to San Diego Bay, California. Dredged by the Albatross, Sta. D 2945 near Anacapa Island, southern California at 30 fms, and by Dr. C. L. Hubbs at Guadalupe Island off Lower California at 40 fms. Microporella californica (Busk), 1856 Plate 44, fig. 2 Lepralia californica Busk, 1856:310. Microporella ciliata form californica, Hincks, 1883 :444. ?Microporella californica, Robertson, 1908 :281, (part). Microporella californica, O’ Donoghue, 1923 :32 ; 1926:65. Microporella californica, Canu and Bassler, 1923 :123. “Cells broadly oval, surface minutely punctured; a lunate pore in front, a little below the mouth; an avicularium on either side above. Mouth rounded above, lower lip straight, four superior spines. Ovicell small, sub-immersed. Hab. California, Dr. Gould.” The above is Busk’s brief description. His figure (plate 11, figs. 6 and 7) represents the species very well, except that his artist appears to have added a row of tremopores distal to the ascopore. The lunate opening of the ascopore, as shown by Busk, is correct. The related form described by Robertson as californica is quite simi- lar in most respects, but has the ascopore closed by a “sieve plate” with small round pores instead of having the usual lunate slit (see M. cribrosa, new species). Otherwise Robertson’s description applies equally well to both forms. 382 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 The zoarium encrusts shells, pebbles and frequently algae. The zooecia are moderately large, 0.60 to 0.70 mm long by 0.40 to 0.50 mm wide (Busk’s figure 7 is within this range), the frontal somewhat inflated and more coarsely punctured than in ciliata; a small umbo often present proximal to the ascopore. The aperture is large for the genus, 0.12 mm long by 0.16 mm broad, rounded distally, the sides considerably incurved to meet the straight proximal border; rarely there are very minute cardelles. The ascopore is slightly elliptical trans- versely with the usual projection from the distal border; this projection and the inner edge of the border minutely dentate. The avicularia are usually paired, one on either side of the ascopore, the mandible long-triangular and sharp pointed, directed forward and slightly outward. The spines are usually 5 (5 to 7), frequently long and heavy, frequently black at the basal joint and occasionally dark throughout. The ovicell is small, compared to the zooecia, and more immersed than usual, width 0.26 to 0.30 mm (the base of young zooecia 0.20 to 0.24 mm), the radiating ribs extending well toward the top which is either smooth or with a low umbo; perforated like the frontal; on the sides extending proximally to the first spines. Hancock Stations: dredged at more than 20 stations from the coast of Oregon southward to the Galapagos Islands (Albemarle and James) ; abundant along shore and about the islands off southern California; Clarion Island west of Mexico; San Esteban Island, Gulf of California ; common in shallow water at shore stations and down to 74 fms. The records of Hincks and O’Donoghue from British Columbia are some- what in doubt, owing to the possible confusion of this species with cribrosa new species, but as I have seen a specimen from Vancouver Island (Ricketts collection) they may be correct. Microporella marsupiata (Busk), 1860 Plate 44, fig. 6 Lepralia marsupiata Busk, 1860 :284. Microporella marsupiata, Norman, 1909 :297. Distinguished by an arcuate or semicircular umbonate process proxi- mal to and partially enclosing the ascopore. The zoarium encrusts shells, corallines, etc. The zooecia are moderate in size, 0.40 to 0.55 mm long by 0.30 to 0.40 mm wide, the frontal smooth to coarsely granular with numerous small tremopores. The aperture shows considerable variation in form, sometimes as high as broad (0.08 by 0.08 mm), or again NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 383 considerably wider (0.07 by 0.10 mm), straight on the proximal border. The bordering sclerite of the operculum is usually dark brown. The peristome is slightly salient with 5 to 7 strong spines which are some- times black at the basal joint; the proximal spine on either side is occa- sionally forked at the tip, as in Busk’s figure (plate 31, fig. 4). The ascopore has a semilunar slit and is finely dentate all around its inner border, with the usual projecting shelf; it is partially surrounded proximally by a semicircular umbonate process (“‘a pouch-like rostrum,” Busk) of varying height and width. The avicularia are single (Busk) or paired at the side of the ascopore (rarely more proximal), with setose mandibles which are directed forward and slightly outward. Busk states that the mandible (‘“‘vibraculum’’) is black, but in our specimens they are only occasionally tinged with brown. The ovicell is large, 0.30 mm wide, globular and prominent, its surface like the frontal, ribbed around the base and in full calcification the lip of the aperture is produced into a strong rib; the sides of the ovicell stop abruptly at the proximal spines. Busk described this species from Madeira and Norman refigured it from the same locality (plate 38, fig. 7). It differs from ciliata in the position of the avicularia and the nature of the ooecium as well as by the presence of the peculiar umbonate process. Hancock Stations: 155-34, Albemarle Island ; 182-34 and 462, James Island ; 810-38, Barrington Island and 435, Chatham Island, Galapagos; 136-34, Clarion Island, W. of Mexico; 234, Baja Point, Lower Cali- fornia. 17 to 73 fms. Microporella pontifica new species Plate 44, fig. 5 Distinguished by the peristome of the fertile zooecia which encloses the ascopore and extends forward upon the ovicell and which is bridged across near the middle to produce two secondary apertures; also by the avicularium which is lateral, proximal to the ascopore and with an aciculate or narrowly lanceolate mandible which is grooved on its under surface. Encrusting on shells and corallines. The zooecia are of moderate size, 0.50 to 0.60 mm long by 0.40 to 0.45 mm wide; the frontal finely granular, less inflated and the separating grooves more shallow than is usual in the genus. The aperture is semicircular, 0.08 mm long by 0.10 mm wide, straight on the proximal border and without cardelles; the peristome of infertile zooecia elevated distally and with 4 to 6 short 384 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 spines. The ascopore is of the usual lunate type with a slightly elevated collar. The avicularium is moderate in size, located usually in the lateral zooecial angle and directed laterally; the mandible, with a complete pivot, has a short triangular base, narrows considerably for a short distance, broadens again into a narrow lanceolate form and ends in an acicular point, the under surface grooved nearly to the tip and a pair of small hooks turned downward at its widest part. Length 0.25 to 0.30 mm. Ovicelled zooecia differ strikingly in appearance due to the extension of the peristome which continues distally across the front of the ooecium and proximally surrounds the ascopore, while on each side is a lappet which bends across to unite with the opposite one and forms a complete bridge on a level with the top of the ovicell; the secondary aperture is thus divided, somewhat unequally into two, the distal one for the ten- tacles, the proximal one for the ascopore. The ovicell is globular, promi- nent, its surface like the frontal and without umbo or ribs, its average width 0.26 mm. Type, AHF no. 81. Type locality Hancock Station 137-34 Sulphur Bay, Clarion Island, W of Mexico, 18°9/05”N, 114°45’25”W, 57 fms. Also Stations 147-34 and 155-34, Albemarle Island, Galapagos; 650-37, E. of San Francisco Island, Gulf of California, and 298, Agua Verde Bay, Lower California, in the Gulf of California; 20 to 60 fms. Microporella tractabilis Canu and Bassler, 1930 Plate 45, fig. 2 Microporella tractabilis Canu and Bassler, 1930 :22. The zooecia are of average size, 0.55 to 0.60 mm by 0.40 to 0.50 mm, finely granulated, with small tremopores and there is no indication of an umbonate process. The aperture is somewhat more than a semi- circle, 0.07 mm long by 0.10 to 0.12 mm wide, straight on the proximal border, the cardelles more prominent than usual. The peristome is thin, slightly raised and bears 4 to 6 small spines. The ascopore is large, nearly straight on its distal border which has a projecting shelf that leaves a lunate opening; the pore is situated farther from the aperture than is usual in the genus, its border only slightly raised. The avicularia peculiar in arrangement, paired, one on either side, distal to the ascopore and directed straight forward parallel to each other; the mandibles are long and setose. Canu and Bassler state (p. 22) ‘the mandibles are NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 385 always long enough to touch the pivot of the avicularia of the adjacent superior zooecia so that all of the avicularia of the same colony are in direct tactile communication.” I have found colonies in which the setae are so long, but this is not always the case even on the same colony. The ovicell is globular, very prominent, granulated and perforated like the frontal and there is only slight evidence of ribs around the base. The paired, parallel avicularia situated far forward easily distinguish this species. Described from the Galapagos Islands, Albatross D.2813 and D.2815. Hancock Stations: 431-35, off Octavia Rocks, Colombia, and 307, Secas Islands, Panama. 40 to 80 fms. Microporella setiformis O’Donoghue, 1923 Plate 44, fig. 8 Microporella setiformis O’ Donoghue, 1923 :32; 1926:65. Encrusting on stones, shells, worm tubes, etc., white and shining. The zooecia are moderate in size, 0.50 to 0.65 mm long by 0.40 to 0.45 mm wide, considerably inflated, elongate hexagonal; the frontal with numerous pores and covered by shining ectocyst. The aperture is more than semicircular, 0.09 by 0.12 mm, the proximal border quite straight and with no indication of cardelles. The peristome is thin, smooth, slightly elevated and there are 5 evanescent oral spines. The ascopore is unusually small, round, slightly elevated and lacks the projecting shelf which is common to most members of the genus. The avicularia are paired, opposite the ascopore near the zooecial margin, the chamber small and rounded, the rostrum short, the mandible setose and usually less than half as long as a zoocium, directed diagonally. The ovicell, which O’Donoghue did not observe, is very prominent, globular, 0.25 to 0.30 mm in width; appearing smooth under the epitheca but when this is removed it is porous like the front and with delicate radiating ribs which are enlarged at the base; on the sides the ovicell extends backward around the aperture to the proximal border. Rarely there is an umbonate process on the frontal. Described by O’Donoghue and recorded by him from 11 localities in British Columbia, from the San Juan Islands northward. Hancock Stations: 1284-41, 1388-41 and 1152, Santa Rosa Island ; 1064, Santa Barbara Island; 1234, off San Pedro, California. Also at Hein Bank, Puget Sound, Washington, Dr. J. L. Mohr, collector. Low water to 54 fms. 386 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Microporella gibbosula Canu and Bassler, 1930 Plate 44, fig. 9 Microporella gibbosula Canu and Bassler, 1930 :20. Zoarium encrusting shells, worm tubes, etc. The zooecia are moderate in size, 0.50 to 0.55 mm long by about 0.45 mm wide, the front swollen and smooth or with fine granules. he aperture is nearly as long as broad, 0.08 mm by 0.09 with the proximal border straight; the peristome low and smooth with 5 small oral spines. The ascopore is round and unusually small, often with a small raised collar. There is one small avicularium (rarely 2) situated usually in the lateral zooecial angle close to the margin, oriented laterally, or slightly oblique, the mandible setiform or somewhat lanceolate. The ovicell is globular, conspicuous, smooth and perforated and only slightly ribbed about the base, width about 0.26 mm. The form of the aperture, the small rounded ascopore and the position of the small avicu- larium appear to be constant and are the most diagnostic characters. Described from the Galapagos Islands, Albatross Sta. D.2813. Hancock Stations: 8 stations among the Galapagos Islands; 431-35, Octavia Bay, Colombia; 114-33, Bahia Honda, and 437-35, Secas Islands, Panama; 309, Port Culebra, Costa Rica; and 298, Agua Verde Bay, Lower California. 5 to 80 fms. Microporella coronata (Audouin), 1826 Plate 45, fig. 1 Flustra coronata Audouin, 1826 :239. Microporella coronata, Waters, 1909 :42. Microporella coronata, Canu and Bassler, 1925 :37. Microporella ciliata var. coronata, Hastings, 1927:340; 1930:727. Encrusting on shells, etc. Zooecia of moderate size, usually between 0.45 and 0.55 mm long by 0.40 to 0.50 mm wide, but varying greatly; distinct, the frontal somewhat ventricose with numerous small pores. The aperture is semicircular, a little narrowed proximally, the proximal border straight, width 0.13 mm, length 0.10 mm; peristome low and thin, with about 6 oral spines the basal joints of which are dark. The avicularia are paired, about opposite the asocopore and directed forward and slightly outward ; the mandible has a hastate shape, the small lateral projections usually bent downward like hooks and inconspicuous, the distal portion slender with a setose point and a curved tip; the rostrum is short, grooved and truncate at the tip, extending only to the lateral projections of the mandible. The ascopore is lunate in form. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 387 The ovicell is large, about 0.26 mm wide, rounded, perforated like the frontal, striated lightly and radially in the young stage; a visor-like projection usually extends above the orifice. In the absence of ovicells this species may be confused with M. pontifex, new species, as both have hastate avicularian mandibles, but in the latter the avicularia are single and quite proximal to the ascopore. When an ovicell is present the peristome at the sides of the aperture is not raised, while in pontifex the lateral peristomial lappets are high and meet above the aperture. It is distributed around the world in warmer waters, and Hastings has recorded it from Coiba, Panama, and Gorgona, Colombia. Hastings also places M. californica (Busk) under the synonomy of coronata, but this is incorrect as the mandible is never hastate and the rostrum is pointed ; also it is a larger and coarser species than coronata. Hancock Station 650-37, E of San Francisco Island, Gulf of Cali- fornia, 47 fms, several colonies. Genus FENESTRULINA Jullien, 1888 This genus differs from Microporella by the stellate character of the tremopores, by the more proximal position of the ascopore so that there are one or two rows of tremopores between it and the aperture, and by the absence of avicularia. Genotype, Cellepora malusii Audouin, 1826. Fenestrulina malusi (Audouin), 1926 Plate 45, fig. 3 Microporella malusii, Hincks, 1884:16. Microporella malusi, Robertson, 1908 :282. Microporella malusii, O’ Donoghue, 1923 :32. Fenestrulina malusii, O’Donoghue, 1926:63. Fenestrulina malusi, Canu and Bassler, 1923:115. Fenestrulina malusi, Osburn, 1940 :433. The zoarium forms white, flat encrustations on shells and stones. The zooecia are moderately large, irregularly hexagonal, sometimes as broad as long, very distinct with deep separating grooves and the front considerably inflated, the surface smooth; the stellate tremopores numer- ous. There is much variation in size of the zooecia, which average about 0.60 mm long by 0.50 mm wide. The aperture is semicircular, with 388 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 a straight proximal border, the peristome low and smooth with 4 or 5 small spines (often entirely wanting). ‘The ascopore is semicircular, like that in most species of Microporella, but is situated farther proxi- mally so that there some tremopores between it and the aperture. The ovicell is large and prominent, perforated and with a row of conspicuous areolae around the base. It apparently occurs around the world in tropical and temperate waters. Hincks and O’Donoghue recorded it from British Columbia; Robertson from La Jolla and Catalina Island, southern California; and Canu and Bassler from the Pleistocene of southern California. The Hancock collections extend the range southward to the Gala- pagos where it was dredged at Charles, Wenman and Albemarle Islands. At intermediate points it was found at Clarion Island, west of Mexico and at several stations within the Gulf of Mexico. It is common about the Channel Islands off the coast of southern California and northward to Oregon. Depth 3 to more than 100 fms. Fenestrulina malusi var. umbonata O’Donoghue, 1926 This variety is characterized especially by the presence of a con- spicuous umbonate process immediately proximal to the ascopore. The measurements are somewhat larger than in the typical form, averaging 0.70 mm long by 0.60 mm wide in our specimens, and the aperture is correspondingly larger. Otherwise there appears to be no essential dif- ference, and there is some intergradation. O’Donoghue described the variety from the San Juan Islands, Puget Sound and from Bentinck Island, and Hincks had already noted its occurrence, without naming it, in the Queen Charlotte Islands. Hancock Station 1325-41, off Santa Catalina Island, southern Cali- fornia, 59 fms. Also from Cadboro Bay, Victoria, British Columbia, G. E. MacGinitie, collector. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 389 Family Eurystomellidae Levinsen, 1909 Zooecia thick walled, without a covering membrane; without pores or with several large fenestrae; aperture very broad, widest at the broadly concave proximal border. Ooecium enclosed in a kenozooecium, the front with a large membranous area. No avicularia, no spines. (After Levinsen). Genus EURYSTOMELLA Levinsen, 1909 Characters of the family, without frontal pores. Genotype, Lepralia foraminifera Hincks, 1883. Eurystomella bilabiata (Hincks), 1884 Plate 58, fig. 5 Lepralia bilabiata, Hincks, 1884:49. Lepralia bilabiata, Robertson, 1908 :298. Eurystomella bilabiata, Canu and Bassler, 1923 :142. Eurystomella bilabiata, O’Donoghue, 1926:65. Zoarium encrusting in a single layer, forming rather coarse layers on stones, shells, etc., reddish or brownish in color. The zooecia are moderately large and very deep, varying much in size, average 0.65 mm long by 0.50 mm wide; broad and rounded distally, narrowed and trun- cate at the proximal end. The front is a heavy, smooth olocyst entirely without pores, often rising into a broad low umbo. The aperture is shaped like a hat with a very narrow brim, rounded distally and sud- denly wider near the proximal border which is nearly straight; 0.20 mm long by 0.30 mm wide. The operculum has the form of the aper- ture, is brown with a darker sclerite which extends all around the border. The ovicell is comparatively quite small, rounded, with a mem- branous area on the top. No avicularia, no spines. Described by Hincks from Houston-Stewart Channel and recorded by O’Donoghue for Brotchie Ledge, Victoria, and Bentinck Island, all in British Columbia. Robertson listed it from Puget Sound, Washing- ton, and Mendocino City and Pacific Grove, California. Canu and Bassler recorded it from the Pleistocene of San Pedro, California. Hancock Stations: 1176-40, Santa Barbara Island and 1130-40, off Laguna Beach, southern California; 275-34, Navidad Head, ‘Tenacatita Bay, Mexico, 19°12’50”N (the most southern record). I have a speci- men from Nootka Island, Alaska, which is the most northern record. It is a rather common species at low tide on rocky shores from California northward, not frequently dredged, but has been taken at 35 fms. 390 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Family Smittinidae Levinsen, 1909 This is a large and varied family, but on the whole is fairly distinct. The frontal is an olocyst with few to many areolar pores, or a pleuro- cyst which develops above the olocyst from the margin inward to the center of the front, or a tremocyst with numerous evenly distributed pores. (Additional pores are often present in the pleurocyst, especially near the proximal end, but these seldom approach the region of the aperture and usually leave an imperforate area proximal to it. The nature of the growth of this layer may be observed on young marginal zooecia.) [The primary aperture is somewhat semicircular (sometimes nearly round, occasionally a little asymmetrical) and usually there are cardelles and a lyrula. The secondary sinus is often well developed proximally. Oral spines are of common occurrence but may be entirely wanting. The operculum is thin and delicate and there is usually no evidence of a vestibular arch. Multiporous rosette plates are the usual means of communication in the lateral and distal walls, but pore chambers (dietellae) may be present. Avicularia are very regularly present, though in individual zooecia they may be wanting, and they are of two categories: (1) median, suboral avicularia in which the avicularian chamber extends across the front to communicate with an areolar pore on each side immediately proximal to the aperture, and (2) frontal avicularia of various forms and sizes. Only the suboral, or only the frontal avicularia may be present, but both kinds are frequently found on the same zooecium. Giant interzooecial avicularia also are occasionally found. The ovicells are hyperstomial, usually prominent at first but often becoming deeply embedded in the later stages of calcification. The sur- rounding zooecia often contribute to the formation of the secondary ooecial layer. The ovicell may be imperforate, it may be perforated by numerous small or larger pores, by a few larger pores centrally placed, or in a few species there is a single central pore (occasionally doubled). SMITTINA, sens Jat. The genera Porella Gray and Smittina Norman have been much confused. Formerly nearly all of the species with a median suboral avicularium were allocated to Porella but later many of these were transferred to Smittina, especially those with a well developed lyrula. The lyrula is rather variable, however, and there has seemed to be no sharp line of division on this basis. There are other criteria to be NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 391 considered, viz., the nature of the calcification of the frontal, the presence or absence of frontal pores and ooecial pores, and the mode of origin of the avicularia. 1. The genotype of Porella is Millepora compressa Sowerby. Un- fortunately when describing this genus Gray misidentified compressa with Millepora cervicornis Pallas, which has somewhat the same growth form but has a porous frontal (tremocyst). As late as 1920 Canu and Bassler accepted cervicornis as the genotype of Porella, but Bassler later (1935) corrected the error. The genotype of Porella therefore has a bilaterally symmetrical avicularian chamber, an imperforate frontal (except the areolar pores), an imperforate ovicell and a very low, broad lyrula which is so short as to be indistinguishable except when viewed from the interior of the frontal, and no cardelles. The other species which may be allied to compressa have the characters mentioned, but the frontal is usually much smoother and is easily mistaken for an olocyst. Careful study of incinerated specimens shows the secondary layer or pleurocyst. In most of the species the frontal becomes very thick, so that the median avicu- larian chamber and the ovicell are often completely buried beneath the secondary crust and the areolar pores are often occluded. Frontal avicu- laria also are sometimes present. 2. The genotype of Smittina is Lepralia landsborovii Johnston which agrees with Porella in the presence of a median bilaterally symmetrical suboral avicularium, but in which the frontal is a tremocyst with numer- ous pores, the ovicell is usually similarly perforated and the lyrula and cardelles well developed. Usually the pores of the ovicell are well dis- tributed, but in a few cases, bella Busk and retifrons, new species, they are limited to 1 or 2 central pores and these may even be occluded in final calcification. The tremocyst often becomes thick and the frontal pores more or less infundibuliform. 3. A third group, Smittoidea new genus, differs in having the frontal a pleurocyst, with a median symmetrically developed suboral avicularium, perforated ovicell and well developed lyrulae. 4. Still a fourth group, Parasmittina new genus, is easily distin- guished by the pleurocystal front and the nature of the avicularia which are variously distributed over the front but never median and suboral; they take their origin from areolar pores on one side only. The lyrulae and cardelles are well developed, though they are sometimes so hidden by the overhanging peristome that dissection is required to reveal their presence. The ovicell is variously perforated, sometimes by small pores or by larger pores which often vary in size and form, or more rarely by one to three central pores. 392 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Key TO THE GENERA OF SMITTINIDAE 1. Frontal an olocyst or pleurocyst, sometimes with numerous pores but the central area at least imperforate ae Frontal a tremocyst with numerous pores over the whole area 2. With suboral avicularia No suboral avicularia . : 3. Avicularia symmetrically deeclocedye in ee Aline Avicularia asymmetrical, close behind the aperture Ramone 4. Avicularian chamber very long, developed from a pore at the proximal end of the zooecum .' . . . . «© & \2euG@gstisella Avicularian chamber short, developed from an areolar pore on each side of the aperture . . . 5 ie eS 5. Lyrula and cardelles small or ee orca impecteente Porella Lyrula and cardelles well developed, ovicell with pores Smittoidea 6. Avicularia variously situated on the front, never median and sub- ONAL os. 7e, pelt Geel Diae STR) ge) eolbsl acd yoeea nace ce nue een eMe am ex Ize Seam iaae a LWW CO WO Avicularia wanting entirely; 2.5. ). os) sks. BA 7. No-lyrula; noumbo . .. 3.6). nl, 0S 8 oe letenclotane Lyrula well developed, umbo (mucro) usually present Mucronella 8. No lyrula, proximal border of aperture broadly arcuate, ovicell closed by operculum . . . . ss 4 ~ Godonelina Lyrula well developed, ovicell not elesed ie the operculum Svznittina Genus PORELLA Gray, 1848 The frontal is a thick pleurocyst with areolar pores, otherwise im- perforate (except rarely a few additional pores near the margins); a suboral median avicularium which is bilateral in origin with narrow tubules extending around the proximal side of the peristome to the areolar pores; lyrula small, short, often also narrow, wanting in some species; cardelles small and low, often wanting. Ovicell hyperstomial, imper- forate, often becoming completely embedded with later calcification. Genotype, Millepora compressa Sowerby, 1805. Most of the species have a smooth frontal, the areolar pores are often occluded in older stages, and the suboral avicularia vary in posi- tion and form, more or less embraced within the “sinus” fold of the peristome or completely proximal to it, the mandible semicircular or pointed in the different species. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 393 Key TO THE SPECIES OF Porella 1. Zooecia large, the frontal more or less costate, no cardelles, no SPIRES "a cally e: lee ie er COT PTESSA Zooecia of moderate size, icuele or not at all Costateh, cy usa eo ae 2. No oral spines, avicularian mandible pointed . . . . acutirostris Small oral spines (2 to 4), mandible not sharp-pointed . . . . 3 3. Avicularian chamber large and prominent, with 2 to 6 pores . . : sae oe les Seen apes oe PONETETE Avicularian Bees ane: Baa less Sere pores usually WAMOMNG | hig Oh ys ar P + 4. Peristome flaring, eacealls at rare Ale e ae no eal 4 ni evanescent spines . . . . : SI onCEE UM DOLCTLS: The secondary aperture is ae the Srauane, projecting Ovennthe apertures ie (ost bcd io abet wis ale sae sus) 5. Zooecia distinct only when young, sorely Beane casnaterele embedded. a. .8 dis ee ; . . Concinna Zooecia remaining distinct, aaieell ateiated sna the base, eahehy strated ai isuiscus) ko. 42. TS eos 63. eolummbiana Porella compressa (Sowerby), 1805 Plate 46, figs. 1-3 Millepora compressa Sowerby, 1805 :83. Eschara cervicornis, Busk, 1854 :92. Porella compressa, Hincks, 1880 :330. The zoarium is erect, bilaminate and branching or flabellate and contorted, arising from an encrusting base to a height of 50 mm. The zooecia are large, averaging about 0.70 mm long, but varying from 0.60 to 1.00 mm, and the width ranges usually between 0.40 and 0.50 mm. The frontal, which is only slightly swollen, is a granular pleurocyst with a row of numerous and well-marked areolar pores and occasionally some additional scattered similar pores near the proximal end; between the areolar pores narrow costal ridges run toward the center; a slightly raised line usually separates the zooecia. The primary aperture is large, about 0.20 mm wide by 0.16 mm long, rounded distally and on the sides, straight on the proximal border where there is a very low lyrula which is nearly as wide as the aperture and which usually cannot be observed except from the inner view of the frontal; cardelles appear to be entirely wanting. The secondary aperture is more or less pyriform, the high, thin peristome rising slightly above the thick frontal wall and enclosing 394 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 the suboral avicularium. The avicularium chamber extends laterally to the areolar pores on both sides but is completely embedded in and obscured by the thick front which rises even above the avicularium so that the rounded mandible often may be seen only by tilting the specimen. There are no spines and no additional avicularia. The ovicell, about 0.24 mm wide, is at first smooth and shining, im- perforate, but soon becomes entirely immersed. This species, the genotype of the genus Porella, differs considerably in appearance from most of the other species which are here assigned to Porella because of the rougher frontal surface, but the imperforate frontal and ovicell, the low, small (vestigial or incipient) lyrula and cardelles (often wanting), with a suboral avicularium, appear sufficient to characterize the group. The species is northern Atlantic in distribution, extending into the Arctic where it is apparently circumpolar. Earlier records are often questionable as it was confused with Smittina (Millepora) cervicornis (Pallas), which has a perforated frontal and which is more southern in distribution. In the Pacific it has not been reported, but at Point Barrow, Alaska, Prof. G. E. MacGinitie has dredged large foliate specimens (Arctic Research Laboratory). Porella acutirostris Smitt, 1867 Plate 46, fig. 4 Porella acutirostris Smitt, 1867 :21 and 132. Porella major Hincks, 1884:51. Porella acutirostris, Waters, 1900 :83. Porella acutirostris, Osburn, 1912 :248 ; 1923: 11D. Porella acutirostris, O’ Donoghue, 1923 :41. Zoarium encrusting on stones and shells, usually in the form of white rounded colonies. The zooecia are elongate-ovate and usually regularly disposed in radiating series, the frontal evenly convex and smooth or slightly granulated, with a row of small areolar pores which often become occluded in later calcification. (Zooecial length 0.45 to 0.60 mm, width 0.30 to 0.45 mm.) The primary aperture is rounded distally, straight on the proximal border with a small, short (often scarcely noticeable) lyrula, or none, and the cardelles are minute and incon- spicuous or wanting. The peristome is high and thin, connected with the sides of the avicularian rostrum but not enclosing it; when an ovicell is present the peristome is connected with it. The avicularian chamber No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 395 is semilunate, broad, extending across the full width of the front to the lateral pores; the rostrum considerably elevated, in the midline and directed toward the aperture which it overhangs slightly; the mandible short-triangular and directed upward and backward at an angle of about 45 degrees. The ovicell is comparatively large, about 26 mm wide, smooth, rounded, prominent and conspicuous; the peristome is sometimes extended across above the orifice in complete calcification. This is a common northern and arctic species, on the Atlantic coast as far south as Cape Cod and along the Pacific coast from Point Barrow, Alaska, to southern California. O’Donoghue listed it from Round Island and Northumberland Channel, British Columbia. Hancock Stations: 1224, Newport Harbor channel, and 1067, Santa Barbara Island, southern California, the most southerly localities. Also Tomales Bay, California (R. J. Menzies, collector) ; Middle Bank, Puget Sound, Washington (J. L. Mohr, collector) ; Stations 20-40 and 100-40, Alaska Crab Investigation; and Point Barrow, Alaska, Arctic Research Laboratory (G. E. MacGinitie, collector). Shallow water down to 60 fms. Porella porifera (Hincks), 1884 Plate 46, figs. 9-11 Porella marsupium form porifera Hincks, 1884 :24. Porella marsupium var. porifera, O’ Donoghue, 1923 :40. Smittina porifera, Canu and Bassler, 1923 :147. Cystisella aviculifera Canu and Bassler, 1923 :152. Smittina marsupium var. porifera, O’ Donoghue, 1926 :69. The zoarium forms small white encrustations on shells and pebbles. The zooecia vary remarkably in size from the center of the colony out- ward, from 0.40 to 0.65 mm in length often in the same colony when free-growing on a plane surface; width 0.30 to 0.40 mm; rhomboid to long ovate. The frontal is considerably inflated in young zooecia but may become nearly flat in advanced calcification; the few areolar pores are sometimes occluded with the thickening of the crust. The primary aperture is a little more than a semicircle, and varies in size with the zooecia, from 0.12 to 0.14 mm in width. The peristome is high and thin, united with the avicularian chamber proximally, lower distally where it bears 4 small evanescent spines; with complete calcification the frontal on the sides may rise to the top of the peristome and fuse with it. The chamber of the suboral avicularium is considerably inflated and extends 396 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 laterally on both sides to the marginal areolae, and is perforated by a varying number of pores, usually 2 to 6 (the areolar pores of the keno- zooecium) ; the rostrum is elevated, directed slightly over the aperture and bears a small avicularium with a semicircular or slightly triangular mandible. Additional small avicularia are usually present on most of the zooecia. Hincks figured them in several positions (Plate 4, fig. 4), most frequently 1 or 2 near the proximal end of the frontal, but often there are several; occasionally they are wanting on most of the zooecia. The ovicell is prominent, round and smooth, 0.16 to 0.18 mm in width, the peristome forming a thin lip above the orifice ; in very advanced calcification the ovicells may become completely immersed. Hincks described it from the Queen Charlotte Island and O’Don- oghue listed it from a number of British Columbia localities. Canu and Bassler recorded it from the Pleistocene of Santa Monica, California. The latter authors also described the form with numerous avicularia as Cystisella aviculifera from the same locality, placing it in that genus because of the absence of lateral areolar pores. However, younger zooecia always show the areolar pores quite distinctly when calcined, small and widely separated with no evidence of costal ridges. It is very probable that the pores of the type material had become occluded with age or fossilization. At any rate it could not remain in the genus Cystisella in which the avicularian chamber rises in connection with the proximal areolar pores and extends the full length of the frontal. Hancock Stations: dredged at numerous stations from the Oregon coast south to Cedros and the San Benito Islands off Lower California, the most southern record at Station 309, Port Culebra, Costa Rica; most abundant about the islands off southern California; 6 to 100 fms. Porella concinna (Busk), 1854 Plate 46, figs. 5-6 Lepralia concinna Busk, 1854 :67. Porella concinna, Hincks, 1884 :24. Porella concinna, Robertson, 1908 :300. Porella concinna, O’ Donoghue, 1923 :40. Zoarium encrusting on shells and stones. The zooecia are of moderate size, averaging about 0.50 mm long by 0.35 mm wide, distinct when young but tending to become immersed in a heavy crust. The frontal is a pleurocyst, shining but somewhat rough in the young stage and becoming rougher and very thick with increasing calcification. The areolar pores are few in number and in older specimens may become completely NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 397 occluded. The primary aperture measures about 0.15 mm in width, rounded distally but somewhat straighter on the proximal border where it bears a broad but very short lyrula, often wanting. The peristome is moderately high but does not rise much above the level of the thick frontal wall; on the proximal side it is connected with the avicularian chamber. The avicularium is round or nearly so and often projects slightly over the aperture; its chamber is large and prominent, rising like a large blunt umbo. It is roughened like the front and bears a few areolar pores which are not conspicuous. The ovicell is rough like the frontal wall and often bears an umbonate process. The species is widely distributed in northern waters. Hincks and O’Donoghue recorded it from a number of localities in British Columbian waters and Robertson from San Pedro, southern California. Not taken in Hancock dredgings. San Juan Island, Puget Sound, (J. L. Mohr, collector) ; Canoe Bay, Alaska, Sta. 26-40 and 160-41, and Alitak Bay, 100-40, (U. S. Alaska Crab Investigation) ; Punuk Island, Bering Sea; Point Barrow, Alaska (G. E. MacGinitie, collector). Porella patens new species Plate 46, figs. 12-13 Zoarium encrusting on shells and stones, unilaminar, white and shin- ing. Zooecia moderate in size, 0.50 to 0.60 mm long by 0.30 to 0.35 mm wide, usually arranged very regularly in parallel rows when on a smooth surface; very distinct. The frontal is smooth, considerably inflated ; several areolar pores on each side, small and often difficult to see except in prepared specimens, often occluded in secondary calcification. The primary aperture is rounded distally and on the sides, the proximal border slightly arcuate and without even a vestige of a lyrula; a small pair of cardelles. The peristome is high, somewhat flaring on the sides which are often raised into short lappets, low on the distal border where there are 4 minute evanescent spines. The secondary aperture sub- quadrangular in form, much larger than the primary aperture, widest proximally, exposing the whole of the aperture. The suboral avicularian chamber is small but extends laterally on both sides to the areolar pores; often with two pores (the areolar pores of the heterozooecium) ; the rostrum high, shaped like a truncated cone and bearing on its tip a small rounded avicularium. The ovicell is high, globular, smooth, the peristome forming a thin lip above the orifice, about 0.20 mm wide and long. 398 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 The species differs in the complete absence of a lyrula and in the spreading form of the secondary aperture which is widest at the proximal end. Type, AHF no. 82. Type locality, Station 1190, Cortez Bank, just south of the United States-Mexican boundary, 32°24/00”N, 119°02’30’W, 131 fms. Other stations: 1187-40 and 1224, Santa Catalina Island; 1190-40, Anacapa Passage; 1294-41 and 1299, Santa Cruz Island, all from southern Cali- fornia; 2160, San Benito Islands west of Lower California; 270, Angel de la Guardia Island, Gulf of California; 328, Cocos Island off Costa Rica; and Wenman Island, Galapagos. Bathymetric distribution 14 to 150 fms. Porella columbiana O’Donoghue, 1923 Plate 46, figs. 7-8 Porella columbiana O’ Donoghue, 1923 :41. Smittina columbiana, O’Donoghue, 1926:69. Zoarium encrusting in a thin, glistening layer. The zooecia are mod- erate in size, 0.45 to 0.55 mm long by 0.25 to 0.35 mm wide, rather regularly arranged; the frontal ventricose, thin and more or less hyaline in younger stages, somewhat thicker and white when fully calcified ; the areolar pores are large and conspicuous at all stages, with short costae which extend toward the center. The primary aperture is slightly wider than long, rounded distally and nearly straight on the proximal border which bears a very low inconspicuous lyrula; the cardelles are minute and often wanting. The peristome is high, especially on the sides, encloses the suboral avicularium proximally and bears 2 or 4 small spines on the low distal border; it fuses with the ovicell of fertile zooecia at the sides but does not develop across the front. The avicularian chamber is con- siderably inflated in young zooecia, bears about 3 small areolar pores and becomes more or less immersed with age; the rounded rostrum rises above the chamber and projects slightly over the aperture, bearing a semicircular or slightly triangular mandible. No frontal avicularia. The ovicell is at first rounded, hyaline and shining, about 0.18 mm broad; with increased calcification a broad collar develops around the base, and a thin-walled area is usually present on the top. Described and listed by O’Donoghue from a number of localities in British Columbia. No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 399 Hancock Collections: Redondo Beach and Santa Monica, southern California, a number of colonies on kelp hold-fasts, washed up on the beach (R. C. Osburn, coll.) ; Friday Harbor, Puget Sound, Washington, collected by Dr. J. L. Mohr. Also dredged at Stations 147-34, Albemarle Island, and 406, 1°03’30”S, 90°17’30”W, Galapagos Islands. The little species is widely distributed along the coast and from shallow water to a depth of 60 fms. Genus SMITTINA Norman, 1903 Smittia Hincks, 1879 (preoc. by Holmgren, 1874). The frontal is a tremocyst with numerous pores; a suboral median avicularium similar in origin to that of Porella; lyrula well developed, and varying in length and breadth; ovicell hyperstomial, usually with numerous perforations similar to the frontal pores. Genotype, Lepralia landsborovii Johnston, 1847. The suboral avicularium is usually included in the peristomial fold of the “‘sinus,”’ but may be quite proximal to it; the front wall is usually thick and the pores are sometimes much enlarged and infundibulate; frontal avicularia are sometimes present in addition to the constant suboral type; the peristome often overhangs the primary aperture and obscures its characters; the ovicell pores are usually numerous and well distributed, but in a few cases they are limited to 1 or 2 central pores and even these may be occluded in final calcification. Key TO THE SPECIES OF Smittina 1. Ovicells with 1 to 3 central pores, sometimes occluded . . . . 2 Ovicells with numerous distributed pores . . . -. +--+ 3 2. Frontal coarsely reticulate; raised separating lines . . . retifrons Frontal with enlarged pores but not reticulate, no separating lines, 1 ooecial pore often closed . . . .- ----- - == Gella 3. Zooecia small, not over 0.45 mm in length, numerous very small ooecial pores; avicularian rostrum denticulate . . . smittiella Zooecia larger,0.60 mmormoreinlength . . ...... 4 4. Umbo very high, pointed, obscuring the small avicularium at its base; ovicell costate, much embedded . . . . . . altirostris Umbo not unusually high, often wanting . . . . ....- 5 5. Peristome incomplete proximally; avicularium usually wanting; frontal coarsely tuberculate . . . - + + + + + ~ cordata 400 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Peristome complete proximally; avicularium usually present; frontal not: tuberculate: Se ee ee : eyes 6. Peristome high, tubular; avicularian rostrum “ovale much ele- vated, in the absence of an avicularium the peristome is CHECULAT Yew say mes wel RLS a Se aeeniigenae Peristome not high and Fabel ee ae . ae 7. Avicularium not enclosed by peristome, its chabiber elongate, mandibleelliptical’. 29). 3 ve: <8 8 6 « Spathulefenn Avicularium enclosed in the Rea sinus fold ’ % “> ) 2. eeee 8. Avicularian rostrum low, chamber small and short; frontal little ventricose . . : oa e ot 8s 6 tandsGorane Avicularian rostrum Hotes SiGe over lyrula; ovicell with a transverse'groove.) 40). 80 ec 5 esd, as, eee ee eee Smittina landsborovi (Johnston), 1847 Plate 47, figs. 1-2 Lepralia landsborovi Johnston, 1847 :310. Lepralia landsborovii, Busk, 1854 :66. Escharella landsborovii, Smitt, 1867 :92. Smittia landsborovii, Hincks, 1880 :341. Smittia landsborovii, Robertson, 1908 :305. Smittia landsborovii, O’ Donoghue, 1923 :42. Smittina landsborovii, O’ Donoghue, 1926 :66. Just what the typical form of /andsborovii may be appears to be in doubt. Johnston’s description is brief and his figure (Plate 54, fig. 9) is inadequate, and we can only be certain that the frontal is smooth and thickly perforated, that the secondary aperture is pyriform and that there is an elongate, slender, pointed lyrula. Busk added the suboral avicularium and figures it (Plate 86, fig. 1) as small rounded and enclosed in the proximal fold of the peristome and the lyrula is broad. Smitt certainly confused two other species with it and only his figure 63 (Plate 24) shows the characters indicated by Johnsten and Busk. Alder (1864:105) gives a more complete description and his figure (Plate 4, figs. 1-3) is evidently of the same species as those of Johnston and Busk. Hincks confused another species with lJandsborovii, as his figures (Plate 48, figs. 7, 8) with imperforate frontal certainly do not belong to this species. How many other errors have been made in recording landsborovii from all parts of the world it is impossible to judge. The form corresponding to the figures of Johnston, Busk and Alder is here described. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 401 Zoarium encrusting (Alder describes it as rising in convoluted frills from an encrusting base) thin and flat. Zooecia large (0.65 to 0.95 mm long, 0.45 to 0.70 mm wide), regularly disposed in series or quincunx, little inflated, the frontal with numerous pores, the marginal ones not enlarged. The primary aperture is rounded, about 0.20 mm wide, with small cardelles and a broad lyrula (in young colonies the lyrula is often narrow, which may explain the pointed lyrulae of Johnston’s figure). The peristome is high and thin, enclosing or at least fusing with the rostrum of the suboral avicularium and the secondary aperture is more or less pyriform (subtriangular on ovicelled zooecia). The suboral avicu- larium is small, little elevated but projecting forward over the lyrula, the chamber small, the mandible semicircular or slightly longer than broad. The large spatulate frontal avicularia described on British speci- mens have not been found on Pacific colonies. The ovicell is comparatively small, 0.26 to 0.30 mm broad, prominent at first but later considerably immersed, porous like the frontal. Cosmopolitan (if the records are all correct). San Pedro, California, Robertson; numerous localities in British Columbia, O’ Donoghue. Hancock Stations: too numerous to list, ranging from the coast of Oregon to the Galapagos Islands. Also from Canoe Bay and Leonard Harbor, Alaska, Alaska Crab Investigation. Smittina spathulifera (Hincks), 1884 Plate 47, fig. 3 Smittia spathulifera Hincks, 1884 :52. The zoarium is encrusting and flat. The zooecia are similar to those of §. landsborovii, as large or even larger, sometimes more than 1.00 mm long, little inflated, regularly arranged in quincunx, with a delicate, slightly raised bordering line. The frontal is a tremocyst with numerous, moderately large pores. The primary aperture is also similar, except that the lyrula is even broader, but the secondary aperture is quite dif- ferent as the peristome does not enclose the avicularium and the lyrula is fully exposed within the short “sinus.” The avicularium is at a little distance from the proximal border of the aperture and is not enclosed in the peristome folds, much larger than in Jandsborovii; the mandible is horizontal and short spatulate or long oval; the chamber varies much in size but is always low and flat and appears to be embedded in the frontal wall, sometimes occupying as much as the median third for nearly half of the frontal length. The frontal pores are naturally occluded in the area occupied by the chamber, but in rare cases when the avicularium 402 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 is absent the pores extend forward to the aperture. No spines. Ovicell wanting in our specimens, but Hincks describes it as large, immersed, the surface roughened and punctured around the edge. Houston Stewart Channel, British Columbia (Hincks). Hancock Stations: 650-37, San Francisco Island, Gulf of California, 24°47'35’N, 110°32’20”W, at 47 fms; and 1258-41, Natividad Island, off Lower California, 27°44717”N, 115°14’20”W, at 66 fms. Also a specimen from off San Pedro, southern California, ‘deep water.” Smittina arctica (Norman), 1894 Plate 47, figs. 13-14 Smittia arctica Norman, 1894:128. Escharella porifera var. majuscula Smitt, 1867 :9, Plate 24, figs. 36-38. Smittina arctica, Norman, 1903 :121. Smittina arctica, Nordgaard, 1906 :29. Zoarium encrusting. The zooecia are usually quite regular in ar- rangement, elongate-ovate; the front considerably inflated, a tremocyst evenly perforated with small pores. The primary aperture is about as wide as long, rounded with the proximal border transverse; the lyrula is of moderate width (Norman, 1903:121, describes it as slender, but it is often as wide as it is long) ; the cardelles small, often scarcely notice- able. The peristome is thin and raised on the sides, embracing the suboral avicularium on the proximal border, more or less fused with the ovicell in fertile zooecia. The avicularian chamber is comparatively small and low, the rostrum projecting slightly over the aperture and bearing a semicircular to subtriangular mandible. The ovicell is quite prominent in the young stage, more or less embedded later, with a few minute pores or punctures and usually with a transverse groove across the top formed by the union of the secondary covering layers. This is an arctic species and is probably circumpolar in distribution. Point Barrow, Alaska, Arctic Research Laboratory, G. E. Mac- Ginitie, collector. Smittina retifrons new species Plate 47, figs. 6-8 Zoarium encrusting shells and the stems of hydroids, uni- or multi- laminar, white or light yellowish, with a shining ectocyst. The zooecia are elongate-hexagonal, regularly arranged in quincunx, averaging in length about 0.65 mm by 0.50 mm in width, distinct in younger stages NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 403 with a raised separating line. The frontal is slightly elevated, with numer- ous large and evenly distributed pores. The pores expand upward to form large infundibuliform pits separated at their rims by narrow walls which produce a coarsely reticulated surface over the whole front. The primary aperture is like that of S. landsborovii (about 0.20 mm wide by 0.18 mm long), with distinct cardelles, but the lyrula is much smaller, seldom as much as one-fourth of the width of the aperture. The secondary aperture is also of the same pattern but is more elevated, especially at the proximal border where it completely surrounds the more elevated avicularium. The avicularium chamber is small (appearing to be entirely median but dissection shows a narrow tube on each side extending to a lateral pore) ; the rostrum elevated, narrow and longitudinally ribbed nearly to its tip; the mandible is semicircular. The ovicell is comparatively small (about 0.25 mm wide), rounded and prominent, smooth or slightly roughened, with a single large rounded pore on the top (more rarely there are two or even three smaller pores). Type, U.S. Nat. Mus., 11030; paratype AHF no. 83. Type locality, Leonard Harbor, Alaska, 20 fms, Alaska Crab Investi- gation station 60-40, several colonies. Also at Canoe Bay, Alaska, shore, station 12-40. Smittina bella (Busk), 1860 Plate 47, figs. 4-5 Lepralia bella Busk, 1860 :144. Smittina bella, Osburn, 1923 :10D ; 1933 :49. The zoarium forms flat, smooth and rather regular incrustations on stones and shells. The zooecia are of moderate size, about 0.55 to 0.70 mm long by 0.35 to 0.50 mm wide, arranged quite regularly. The frontal is a tremocyst with moderately large pores, slightly inflated in the young marginal zooecia but becoming quite flat with age so that the zooecial borders are indefinite. The primary aperture (marginal zooecia) is nearly round, straight on the proximal border where there is a short, narrow, truncate lyrula; the cardelles small and low. The primary peristome is low and thin and soon becomes completely obscured by the thick frontal wall which forms the secondary aperture; this is more or less pyriform, at the level of the general crust, and encloses the small median suboral avicu- larium with a semicircular mandible. In very young marginal zooecia the avicularian chamber is lunate and extends across the front from one areolar pore to another on the opposite side, but the chamber soon becomes 404 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 covered by the frontal crust; in older zooecia all that is seen of the avicu- larium is the mandible enclosed in the proximal border of the secondary aperture. The ovicell is rounded, about 0.26 mm in width and very soon be- comes completely immersed beneath the secondary crust of the two lateral and the distal zooecia which usually leave a large irregular pore at the point of junction. This is an arctic and northern species, on the Atlantic coast occurring as far south as Mount Desert Island, Maine. Osburn recorded it from Point Barrow and Icy Cape, Alaska (Canadian Arctic Exped.). Point Barrow, Alaska, G. E. MacGinitie (Arctic Research Labora- tory). Smittina smittiella Osburn, 1947 Plate 47, figs. 11-12 Smittina smittiella Osburn, 1947 :37. ? Escharella landsborovi var. minuscula, Smitt, 1873 :60. Smittina species, Marcus, 1938 :44. The zoarium is encrusting, small, the largest colonies I have ob- served are not more than 5 mm across. Apparently they mature very rapidly as zooecia of the second row from the ancestrula are often pro- vided with ovicells. The zooecia are rather small (average about 0.45 mm long), regu- larly arranged, distinct, the frontal somewhat inflated and with numerous pores. The primary aperture is rounded, with small cardelles and a broad lyrula with laterally projecting corners. The median avicularium is small, its mandible short oval (a little broader at the tip), elevated and project- ing above the lyrula, and the tip of the rostrum is finely serrate or denticulate across its upper border. The avicularian chamber is short but extends laterally on both sides to marginal areolar pores. The peri- stome is elevated into lappets on the sides, lower but continued around the aperture distally on the infertile zooecia, low proximally and leaving a rather deep secondary sinus on either side of the avicularian rostrum. The ovicell is comparatively large, about 0.24 mm wide, prominent, with pores similar to the frontal. Osburn listed the species from the southern shore of the Caribbean Sea and Pensacola, Florida: Smitt’s specimen was from Pourtales’ Florida collections, and Marcus recorded his “Szittina species” (which he assures me, in /itt., is smittiella) from the Bay of Santos, Brazil. It is therefore a special pleasure to record this little species from the Eastern Pacific. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 405 Hancock Stations: 316-35, Indefatigable Island, 0°33’35’S, 90°10’ 40”W, 20 fms; 136-34, Albemarle Island, 80 fms; 143-34 off Wenman Island, 100 fms, and 147-34, Albemarle Island, 30 fms, Galapagos; 205-34, La Libertad, Ecuador, 8 to 12 fms. Smittina altirostris new species Plate 47, figs. 9-10 Encrusting on a shell. Zooecia characterized by the high, erect, conical process on the median line proximal to the aperture; size mod- erate, 0.40 to 0.50 mm long by 0.25 to 0.35 mm wide; distinct and separated by deep grooves. The front is a tremocyst with relatively few large pores over the whole surface, considerably ventricose even in com- plete calcification. The primary aperture is broader than long, about 0.16 mm broad by 0.14 mm long; the lyrula very broad, straight across the tip and the angles extended laterally into points. The suboral avicu- larium is small, rounded with a semicircular mandible and is difficult to observe beneath the high process. The secondary aperture is pyriform with a rather broad sinus through which the lyrula may be seen, even in older stages. The peristome is moderately thick-walled and extends to the base of the process, enclosing the avicularium. Two or three small distal spines may be present on the younger zooecia, but are very evan- escent. The median frontal process is sharp-pointed, granular and white at the tip; rarely there are two of these, one on either side of the mid- line, and also not infrequently there is a similar but smaller process distal to the aperture on the base of the succeeding zooecium. Frontal avicularia are rare, but a small one with a triangular mandible is occa- sionally present at the side of the peristome. Ovicell small, 0.20 mm wide, with radiate costal ridges and much embedded. Type, AHF no. 84. Type locality, Nunivak Island, Alaska, one colony, 8 to 10 fms (no further data). Smittina maccullochae new species Plate 48, figs. 5-6 Porella collifera, Canu and Bassler, 1923 :148. Zoarium encrusting, usually unilaminar, with a rough surface. The zooecia are large and quite variable, ranging from 0.65 to more than 1.00 mm in length by 0.40 to 0.60 mm in width; the most noticeable features being the coarse tremocystal front and the erect tubular peristome 406 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 which bears a small suboral avicularium on its proximal lip. The front is evenly arched, except in extreme calcification and there is sometimes a salient thread in the separating grooves; the pores are large, evenly distributed, there is no apparent distinction between the marginal and frontal pores, and there is no umbo or other type of surface irregularity. The primary aperture is rounded, nearly straight on the proximal border with a conspicuous lyrula which is about one-third as wide as the aperture and excavated at the tip. The peristome is an erect tube, continuous around the aperture, usually bearing a small suboral avicularium which is carried up on the edge of the proximal rim, and it is continued on the ovicell above the orifice. The avicularium is small, oval and usually at the level of the peristome but occasionally it is less elevated than the peristome which is then notched proximally; the avicularia are some- times wanting on some of the zooecia but I have never found them en- tirely absent on any colony. The primary ovicell is comparatively small and prominent, but with complete calcification it measures 0.40 to 0.45 mm in width by 0.30 to 0.35 mm in length, thick walled with large pores like the frontal and with the peristome extending across above the orifice. By some unhappy accident this species was listed by Canu and Bassler from the Pleistocene of Santa Barbara, California, as Robertson’s Smittia collifera, which is quite another species. Dr. Bassler has kindly checked the identification of his material for me. Aside from Canu and Bassler’s reference the species has apparently not been previously observed. It is a fairly common species along shore and about the islands off southern California, not noted north of Santa Barbara, California, nor south of the San Benito Islands, Mexico (Lat. 28°17/15’N). This species is dedicated to Dr. Irene McCulloch of the Hancock Foundation, whose interest and help have contributed in many ways to the completion of this monograph. Type, AHF no. 85. Type locality, Hancock Station 1295-41, Santa Cruz Island, Cali- fornia, 34°00’30”N, 119°31’30”W, at 19 fms. Other localities: Sta. 894-38 and 1279-41, San Miguel Island; 1143-41, Portuguese Point; 1217-41, Point Fermin; 1280-41 and 1283-41, Santa Rosa Island ; 1300- 41, Santa Cruz Island; 1407-41, Santa Catalina Island, and San Pedro and Newport Harbor, all from southern California. Station 1250-41, San Benito Islands, off Lower California. Also from the Lower Pleisto- cene, Timms Point, California, collected by G. P. Kanakoff. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 407 Smittina cordata, new species Plate 48, figs. 1-4 Zoarium encrusting, usually unilaminar, the surface often irregular. The zooecia are large, 0.65 to 0.85 mm long by 0.40 to 0.55 mm wide, distinct in younger stages, with a raised line in the separating groove; the frontal is a little inflated, a coarse tremocyst with large pores, the areolar pores usually larger, the frontal granulated in the young but in complete calcification often with irregular umbonate thickenings which occasionally cover nearly all of the frontal area. The primary aperture is subcordate (slightly narrowed distally, but sometimes more nearly round) length 0.22 to 0.25 mm, width 0.20 to 0.22 mm, with distinct cardelles and a small but distinct lyrula which is quadrate, or double pointed. The peri- stome is thin, somewhat elevated on the sides, less raised on the distal border and usually wanting entirely on the proximal border above the lyrula, which is always fully exposed. Only rarely there is a small oval suboral avicularium which is not enclosed by the peristome; frequently whole colonies are without avicularia and when present they are never numerous and never much elevated, but the chamber extends across the front in a narrow lunate cavity proximal to the aperture. The ovicell is large, 0.35 to 0.40 mm wide by about 0.30 mm long, thick walled and porous like the frontal. The most striking feature of this species is the almost complete absence of the suboral avicularia, always rare and often they are wanting over whole colonies. This character, with the usually low peristome gives the aperture a wide open appearance revealing the whole of the lyrula and the proximal border. Occasionally the peristome rises rather high on the sides and more rarely may be complete proximal to the aperture. Type, AHF no. 86. Type locality, Catalina Island, southern California, 30 fms. Also at stations 1284-41 and 1410-41, Santa Rosa Island; 1271-41, Anacapa Island; 1232-41 off San Pedro Breakwater; Redondo Beach, and on a shell from an Indian kitchen midden at Dana Point, southern Califor- nia; 1889-49, Cortez Bank and 871-39, Coronado Islands near the United States-Mexican boundary; Dewey Channel off Point San Eugenio, Lower California; and Raza Island, Gulf of Mexico, 28°48’N, 113°W, the most southern locality. Near shore to 40 fms. 408 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Genus SMITTOIDEA new genus The frontal is a granular pleurocyst, surrounded by a row of con- spicuous areolar pores which are separated by short costal ridges. There is a median suboral avicularium, enclosed within the peristomial sinus fold or proximal to it. Lyrula and cardelles well developed. The ovicell is hyperstomial and perforated by numerous, evenly distributed pores. Genotype, Smittoidea prolifica Osburn, new species. Key To SPECIES OF Smittoidea 1. Avicularium with a long-pointed mandible which is directed back- ward and located proximal to the peristome . . . . reticulata Avicularium enclosed by the sinus fold of the peristome . . . 2 2. Avicularium with a semicircular mandible directed more or less Vectically cue os © Chel 6 Sol 4 aera, Avicularium with a Dea, eae which is directed laterally, more or less enclosed by the sinus fold of the peristome transversa Smittoidea prolifica new species Plate 48, figs. 7-8 Smittia reticulata, Robertson, 1908 :306. Zoarium small, white, encrusting on stones, shells and stems. The zooecia are of moderate size, 0.40 to 0.50 mm long by 0.25 to 0.30 mm wide, ovate or irregularly hexagonal, somewhat swollen and very distinct. The frontal is a pleurocyst, smooth when young but becoming granular with age; a single row of rather large areolar pores and between these are distinct short ribs which run part of the way toward the center. The primary aperture is nearly circular, rounded distally and on the sides and straighter on the proximal border, about 0.13 mm wide by 0.12 mm long; the lyrula large, its tip transverse and the angles usually extended laterally; the cardelles strong, pointed. The peristome rises sharply on the sides, descending to the distal border where there are 2 to 4 evanescent spines ; proximally the peristome forms a somewhat quadrate sinus which encloses the suboral avicularium. The avicularian chamber is low and small and connected on each side with an areolar pore by a narrow tubule, the rostrum is somewhat elevated and bears a small rounded avicularium and often partially obscures the lyrula. Frontal avicularia are wanting. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 409 The ovicell is comparatively large, 0.24 to 0.28 mm wide, very prominent, with numerous pores each of which is slightly tubular; the peristome joins the proximal corners of the ovicell but is not continued across the front. The species is unusually prolific, nearly every zooecium, except the first 2 or 3 rows, bearing an ovicell. This species differs from 8S. reticulata, with which Dr. Robertson placed it, in a number of ways, especially in the nature of the avicularium, the characters of the ovicell and the appearance of the frontal. Miss Robertson described and listed it from La Jolla, California, and the Coronado Islands, just south of the Mexican border. The S. reticulata of Okada and Mawatari (1936:64) appears to be the same as they refer to the avicularium as “oval or elliptical, somewhat elevated, placed just below the rimule on the median longitudinal axis of the zooecium.” Since the species appears not to have been properly recognized it is named, as a new species, for its remarkable reproductive capacity. Type, AHF no. 87. Type locality, Hancock Station 1449-42, Newport Harbor, southern California, on a float, 34°35/47”N, 117°52’55”W. Also taken at Han- cock Stations: 1178-40, Santa Catalina Island; 1217-40, Point Fermin; 1232-41, off San Pedro Breakwater ; 1283-41, Santa Rosa Island; 1295- 41 and 1662-48, Santa Cruz Island; all from southern California. Also Albatross Station 2945, southern California, and San Ignacio Lagoon, Lower California, Dr. C. L. Hubbs, collector. It is a common species on piles and floats and along shore and down to 45 fms, but has not been noted north of Point Conception, California, nor south of the San Ignacio Lagoon, Lower California. Smittoidea reticulata (MacGillivray), 1842 Plate 48, figs. 9-10 Lepralia reticulata J. MacGillivray, 1842 :467. Smittia reticulata, Hincks, 1880 :346. Smittina reticulata, Nordgaard, 1918 :60. Smittina reticulata, Canu and Bassler, 1929 :337 ; 1930 :27. Not Smittia reticulata, Robertson, 1908 :306 (see Smittoidea prolifica). The zoarium encrusts shells, corallines, etc., small, white or pale yellow. The zooecia are moderate in size, 0.40 to 0.55 mm long by about 0.30 mm wide; ventricose and distinct when young but becoming nearly flat with age; the frontal a coarsely granulated pleurocyst with con- spicuous areolar pores which have high ribs between them. The primary aperture measures 0.12 mm in width by 0.10 mm long, rounded with 410 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 a more transverse proximal border which bears a moderately large lyrula with laterally extended points; the cardelles are strong and bluntly pointed. The peristome is elevated, thin, bearing 2 to 4 small evanescent spines on the distal border, the proximal border higher and extended proximally into a deep rounded sinus which is broad enough to expose at least a part of the lyrula. The avicularium is usually median (often slightly to one side of the midline), slightly raised, the narrow and long-pointed mandible directed proximally; it is rather unique in that it is placed entirely proximal to and separated from the fold of the peristomial sinus. In spite of this separation and frontal position the species appears to belong with those which have the median suboral avicularium, as the avicularian chamber is continued as a narrow tubule around the base of the peristome on both sides. The ovicell is comparatively large, about 0.26 mm wide, the front finely granulated, with numerous small pores, and the base surrounded by a thick collar; becoming more or less immersed with age. As Marcus (1938:46) has already pointed out, the S. reticulata of Robertson, from California, and that of Okada and Mawatari, from Japan, with a rounded avicularium enclosed in the peristomial sinus, cannot be reticulata but another species. (See S. prolifica.) The species has a very wide distribution, if the records can be trusted, from Australia, where it was described, to northern Norway and around the world. It has hitherto been noted in the Eastern Pacific only at the Galapagos Islands (Canu and Bassler, 1930:27), and apparently it is not common in this region as only a few colonies were noted at the various localities. Hancock Stations: 155-34, Albemarle Island; 170-34, Chatham Island; 411, Duncan Island; 430, Wenman Island, and 439, James Island, Galapagos; and 580-36, San Marcos Island; 249, Isla Partida, and 275, Raza Island, Gulf of California. 20 to 150 fms. Also the writer has a specimen from Halape, Hawaii, collected by Dr. R. W. Hiatt. Smittoidea transversa (Busk), 1884 Plate 48, fig. 11 Smittia transversa Busk, 1884:152. Zoarium encrusting, multilaminar. Zooecia of moderate size, 0.40 to 0.55 mm long by 0.30 to 0.40 mm wide, alternating in series and some- what hexagonal in form. The front is a slightly ventricose, granulated pleurocyst; the areolar pores conspicuous, with a few additional frontal pores. The primary aperture is nearly round, 0.13 mm wide; the lyrula NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 411 moderate (one-third the width of the aperture). The secondary aper- ture is irregularly pyriform, the peristome with a low lappet on each side and proximally it embraces the transverse avicularium in an unsym- metrical notch; it is wanting distally where 2 small evanescent spines are rarely present. The suboral avicularium is median in character though sometimes slightly at one side of the midline; the elongate curved rostrum often makes it appear assymmetrical when the chamber is median; the mandible is ogival or triangular in form, the tip strongly decurved; the avicularian chamber is not prominent. The ovicell is rounded or slightly elongate, 0.20 to 0.24 mm wide; a broad collar surrounds the base leaving a central rounded area on the top which is perforated by numerous small pores. The type of suboral avicularium is unusual. Busk described the species from Australia (Challenger Sta. 163a) and it does not appear to have been noticed since. Hancock Station 1344-41, south of San Nicholas Island, southern California, 32°53’00"N, 119°23’45”’W, one colony at 75 friis. Genus PARASMITTINA, new genus Avicularia variously distributed on the frontal, but never median, suboral and bilaterally symmetrically developed around the proximal border of the aperture; they take their origin from areolar pores on one side. The frontal is a pleurocyst with a row of areolar pores and occa- sionally there are some additional pores, usually at the proximal end; the lyrula and cardelles usually well developed, though the overhanging peristome in some cases may require dissection to expose them. The ovicell is variously perforated, by numerous small pores, by several larger ones which may vary in size and form, or more rarely by 1 to 3 central pores. Genotype, Lepralia jeffreysi Norman, 1876:208. The essential differences between this group and Smittina (sens str.) are in the nature of the frontal and the avicularia. The frontal is a pleurocyst, and even in the occasional zooecia which have additional pores inside from the areolar row the pleurocystal layer is seen to develop from the border toward the center; young marginal zooecia show this manner of growth, especially after incineration. The avicularia are vari- ous in size, form and distribution, but the chamber is never bilateral ; they may be oval, spatulate, short-triangular or long-pointed and range from minute to gigantic, and they may sometimes be interzooecial ; not infrequently there may be several forms and sizes on a single zooecium ; they often vary greatly on the same zoarium. 412 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Key To SPEcIEs OF Parasmittina 1. Ovicell with 2 or 3 large central pores . . . . . = « jepreysz Pores of ovicell more numerous . +. = > = « i Sie 2. Peristome high, forming a complete tube . . . . . . tubulata Peristome not forming a high tube . . . oon ee 3. Small, less than 0.45 mm long; lyrula very ea + aces, Sle ann ae aa Larger «0-502, to 0:60) sma en ees ae °. a, Ce 4, Giant pointed avicularia directed eae anal ligulate avicu- laria at side of aperture . . «ses @ _ o) Seu emasenemapee Giant pointed avicularia directed fee ss tre ls es 5. Giant avicularia long-pointed or subspatulate, not elevated, directed more or less laterally distal to the aperture . californica Giant avicularia with the tip elevated, below or at one side of the aperture, directed ‘distally . < . |<. .« hres pene 6. One to several high frontal tuberosities ; giant avicularia with broad triangular mandible, the point much elevated . . collifera No such frontal tuberosities . . . 8 ie 7. Frontal very thick and covered with fell poate granules, a rounded embedded avicularium at the proximal end . alaskensis Frontal only moderately thick, avicularia different . . . . . 8 8. Primary aperture longer than wide, peristome developed only on the sides, avicularia spatulate oroval . . . . . . spathulata Primary aperture not longer than wide, peristome usually devel- oped on the proximal border, avicularia pointed . . trispinosa Parasmittina trispinosa (Johnston), 1838 Plate 49, figs. 7-8 Discopora trispinosa Johnston, 1838 :222. Lepralia trispinosa, Johnston, 1847 :324. Escharella Jacotini, Smitt, 1867:11. Smittia trispinosa, Hincks, 1880 :353. Smittia trispinosa, Hincks, 1884:25 (‘‘Several varieties occur.’’) Smittia trispinosa, Robertson, 1908 :302. Smittia trispinosa, O’Donoghue, 1923 :43. Smittina trispinosa, O’ Donoghue, 1926 :67. Smittina trispinosa, Canu and Bassler, 1930 :27. Smittina trispinosa, Hastings, 1930 :726. If all the varieties which have been described under this species really belong here, it is probably the most variable species known. It has been given cosmopolitan distribution, which may be quite correct, but it is NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 413 also possible that more careful analysis would show further distinctions in various parts of the world. Most of the varieties have been based on the form, size and distribution of the avicularia and the height and form of the peristome and no one can deny the variability of these structures in P. trispinosa, but the size and form of the primary aperture, the char- acters of the operculum, lyrula, cardelles, ooecium, etc., have usually been neglected. In all of the numerous specimens similar to trispinosa on the Pacific coast, from Alaska to the Galapagos, which have come under my observation, none are exactly like those from western Europe. The nearest approach to identity is among the northern specimens, from Alaska to British Columbia. Farther south the peristome is usually lower and less spout-like and the aperture somewhat larger. The avicularia near the peristome also are usually much larger than in the northern specimens. The zoarium is encrusting, often becoming multilaminate and nodular or even erected in low folds. The zooecia are moderate in size, 0.45 to 0.60 mm long by about 0.30 mm wide, but varying greatly in both size and form; the primary layer growing on a flat surface is quite regular with the zooecia in parallel series, but in the secondary layers they may be turned in all directions; distinct only in younger growth stages which often are slightly ventricose and have raised separating lines. The frontal is a pleurocyst, granular or irregularly roughened, with a row of areolar pores (occasionally a few additional pores). The primary aperture in marginal zooecia averages 0.11 mm in width by 0.10 mm in length, rounded except on the proximal border where there is a moderately devel- oped lyrula; the condyles small. The peristome is thin, high on the prox- imal border where it is often somewhat notched, sloping downward on the sides and wanting on the distal border where there are 3 (2 to 4) spines; the overhang of the peristome usually obscures the lyrula and condyles. The avicularia are variable; the most characteristic type is moderately large, located a little proximal and to one side of the peristome, the long- triangular rostrum elevated and directed more or less distally beside the peristome, there is much variation in the size; frequently there are other avicularia, varying in size and form distributed irregularly over the frontal. Ovicell prominent, the frontal surface usually a little flattened, with moderately large pores that vary in size and form; width 0.26 mm; in full calcification the front often becomes rough and the ovicell much embedded. The above description applies to more northern and English speci- mens; farther south on the Pacific coast there are minor differences, such as: the aperture is slightly larger; the giant avicularia are usually larger 414 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 and more erected, and there seems to be a tendency toward a larger number of frontal pores in addition to the areolar pores. In its various forms the species is cosmopolitan. In the Eastern Pacific area it has been noted by Hincks, Robertson, O’Donoghue, Canu and Bassler and Hastings, all the way from British Columbia south to the Galapagos Islands. Hancock Stations: dredged and collected along shore at more than 60 stations from Oregon to the Galapagos Islands. In the collections also are specimens from Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector; from southern Alaska; and from Puget Sound, Dr. J. L. Mohr, collector. Parasmittina jeffreysi (Norman), 1876 Plate 49, figs. 5-6 Lepralia Jeffreysi Norman, 1876 :208. Smittina Jeffreysi, Norman, 1903 :120. Smittina Jeffreysii, Levinsen, 1916 :458. Zoarium broadly encrusting, or rising into tubular or folded expan- sions which are sometimes branched. The zooecia near the growing edge are moderately large, averaging about 0.65 mm long by 0.40 mm wide, regularly arranged in quincunx, elongate-ovoid with the proximal end usually narrowed between the adjoining zooecia. The frontal is only slightly elevated, a granulated pleurocyst with a row of conspicuous areolar pores. The primary aperture measures about 0.16 mm in either direction, broadest at the proximal end which is nearly straight ; cardelles of moderate size; the lyrula broad at the base and narrowed toward the tip which is truncate. The peristome is low, slightly higher on the sides, usually exposing the whole of the aperture; the distal border with 2 to 4 evanescent spines. There are two kinds of avicularia; a large triangular one on the front proximal to and at one side of the aperture, the rostrum elevated and the pointed mandible directed forward beside the peristome, frequently wanting, and smaller elliptical avicularia scattered over the front, sometimes numerous, not elevated and variously oriented. The ovicell is prominent, rounded, large (0.35 to 0.40 mm wide), the surface granulated like the frontal and bearing 3 (2 to 4) conspicuous pores, each with a slight collar. This is a common arctic species known from Spitzbergen to Green- land and south to Labrador. Very common at Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. Evidently it is circumpolar in distribution. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 415 Parasmittina spathulata (Smitt), 1873 Plate 49, figs. 12-14 Escharella Jacotini var. spathulata Smitt, 1873 :60. Smittina trispinosa var. spathulata, Osburn, 1914 :208 ; 1927 :29, (spathulosa, by error) ; 1940:435. Smittina trispinosa spathulata, Canu and Bassler, 1928 :114. Zoarium encrusting, usually in a flat smooth layer, white and shining. Zooecia moderately large, 0.55 to 0.75 mm long by 0.40 to 0.50 mm wide, indistinct but sometimes there is a low separating line; the front nearly flat, a pleurocyst with small shining granules; areolar pores of moderate size. The primary aperture is slightly longer than wide, 0.14 mm long by 0.12 mm wide; the rather narrow lyrula always visible, the cardelles larger than usual in the genus. The peristome is limited to a distinct lappet on each side. The avicularia are usually spatulate or oval, but may be ligulate or more rarely pointed, variously located, and usually directed proximally ; sometimes there is a large spatulate avicularium at one side of the aperture directed proximally. The ovicell is round, about 0.26 mm wide, moderately prominent, with a few rather large pores; the peristome connects with it and may be continued across the border of the orifice ; in older stages the pleurocyst of the succeeding zooecium may form a basal collar and may even cover a considerable portion of the ovicell. It is an abundant form in the Gulf of Mexico and the Caribbean Sea and apparently has not been reported elsewhere. The S. reticulata var. spathulata of MacGillivray, 1882:135, is evidently a different species. I believe the characters are sufficiently different to warrant its elevation to specific rank, especially on the basis of the elongate primary aperture and the nature of the secondary aperture. Hancock Stations: 55-33, Charles Island; 143-34, Wenman Island ; 155-34, Albemarle Island, and 201-34, Hood Island, all from the Gala- pagos Islands. 25 to 100 fms. Parasmittina californica (Robertson), 1908 Plate 51, figs. 8-11 Mucronella californica Robertson, 1908 :308. Zoarium encrusting, rather coarse. Zooecia moderately large, averag- ing about 0.60 mm long by 0.40 mm wide, irregularly quadrangular, distinct with rather deep grooves. The front wall is heavily calcified ; it has somewhat the appearance of a tremocyst with a small number of large infundibuliform pores similar in size to the areolar pores, but the 416 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 secondary layer is laid down by growth from the areolar pores toward the center in the fashion of a pleurocyst. The peristome is thin and usually low, but sometimes rises to a considerable height on the sides and may surround the proximal border of the aperture. The primary aperture is nearly round, only slightly wider than long (0.15 mm wide) ; the lyrula moderately developed, not more than one-third the width of the aperture, transverse at the tip and the corners not extended. Small, pointed, oval or short-spatulate avicularia are variously dis- tributed on the front and usually directed laterally; at the side of the peristome there is frequently a giant avicularium with a long sub- spatulate mandible (the sides gradually narrowing toward the tip) directed forward and often somewhat curved around the peristome, the mandible as long as 0.40 mm but usually shorter. The oral spines number one to three, small and very evanescent. The ovicell is large, about 0.35 mm in width, roughened and heavily calcified like the frontal, with a few large pores and with the peristome extended across the front. This is evidently the species which Dr. Robertson described as a Mucronella, but the supposed mucro is undoubtedly a lyrula and the peristome extends behind it; the presence of avicularia similar to those common in Parasmittina and the nature of the ovicell also relate it to the latter genus. Robertson recorded it from “‘several localities on the coast of southern California,” and “dredged off the island of Santa Catalina.” As in many other species there is a distinct bathymetric change to the southward; all of the southern California localities are less than 50 fms, those in Mexican waters are around 50 to 60, and the one Galapagos station was 100 to 150 fms. Hancock Stations: 1281-41, Santa Rosa Island; 1327-41, San Cle- mente Island; off Santa Catalina Island, off La Jolla and several other localities without specific data, southern California. Stations 1008-39 and 1250-41, San Benito Islands, and 1264-41, Cedros Island, off Lower California; 557-36, Isla Partida, Gulf of California, and 143-34, Wen- man Island, Galapagos. Parasmittina collifera (Robertson), 1908 Plate 49, figs. 9-11 Smittia collifera Robertson, 1908 :304. Smittia collifera, O’ Donoghue, 1923 :43. Smittina collifera, O’Donoghue, 1926 :68. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 417 (Not “Porella collifera Robertson,” Canu and Bassler, 1923 :148.) Zoarium encrusting, the secondary layers often rough and nodulous. Zooecia of moderate size, averaging about 0.50 mm long (range 0.40 to 0.65 mm), the width between 0.30 and 0.40 mm. In the primary layer the zooecia are regularly disposed in quincunx, the form ovate or elongate-hexagonal; the frontal is a coarsely granulated pleurocyst, with moderately large areolar pores and usually a few additional pores (espec- ially near the proximal end). The extra frontal pores often give the appearance of a tremocyst, but this is nullified by their occasional com- plete absence, and in young zooecia the pleurocyst may be observed to develop from the zooecial borders above the olocyst. The frontal prom- inences or colli (hills) which characterize the species are often but little developed on the primary layer, usually 1 to 3 small but rather high, erect knobs, but in later growth the tubercles may be broad and heavy and sometimes nearly cover the front. The primary aperture is nearly round, slightly longer than broad (0.16 mm long by 0.15 mm wide), with strong cardelles and a moderate lyrula which is considerably wider at its base and truncate at the tip. The peristome is thin and little elevated, sometimes forming a secondary sinus on the proximal border but always leaving the lyrula and aperture well exposed; 2 long spines are present on the distal border in young zooecia. The avicularia are of three kinds: (1) small to large, semi-erect, with a triangular mandible directed distally, located proximal to and usually at one side of the peristome; (2) small ovate avicularia variously situated on the front or replacing the triangular ones beside the aperture ; (3) rarely an elongate-spatulate avicularium replacing an oval one on the frontal. The ovicell is large, 0.25 to 0.30 mm in width, rounded and con- spicuous, with several (6 to 8) large pores which vary in size, form and disposition; with complete calcification the ooecial cover often be- comes very rough, with protuberances similar to those on the frontal. This species is evidently a member of the S. trispinosa group, but it is differentiated by its larger size, especially of the primary aperture, and by the conspicuous erect frontal nodules or protuberances. Described from the Coronado Islands, Mexico, a little south of the harbor of San Diego, California, which appears to be about its southern limit. O’Donoghue listed it from numerous localities in British Columbia. Hancock Stations: dredged at numerous localities from Oregon south to the islands off the coast of southern California; common also at various shore stations. 418 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Parasmittina crosslandi (Hastings), 1930 Plate 48, fig. 12 Smittina crosslandi Hastings, 1930:726. Smittina trispinosa, Canu and Bassler, 1930:27 (in part). Zoarium variable in form, the primary layer often broadly encrusting, the secondary, multilamellar growth nodular and frequently rising to form rounded, crooked stems, which branch irregularly; scarcely any two colonies entirely alike in form. Zooecia of the primary layer rather regularly arranged in quincunx, elongate-hexagonal or somewhat quadrate, distinct with a raised sepa- rating line, average length 0.45 mm (0.40 to 0.65), width about 0.30 (0.25 to 0.40) mm. In the secondary layers the zooecia vary greatly in form and arrangement. The frontal is a granular pleurocyst with a row of rather large areolar pores around the margin. The primary aperture is rounded, more transverse on the proximal border, with well developed cardelles and moderate lyrula which is long and truncate at the tip; width 0.10 or 0.11 mm. The secondary aperture is ‘‘spout- shaped,” the peristome high on the sides, descending toward the distal border and with a deep narrow “sinus” on the proximal border, the lateral wall sometimes slightly folded in older zooecia. In marginal zooecia 3 to 5 oral spines are often present. The avicularia are various, small or large long-pointed ones near the aperture and directed proxi- mally, small ligulate ones beside the aperture, and small to large oval ones on the frontal, all directed proximally; there is much irregularity in their occurrence, but the small ligulate ones are the most characteristic. The ooecia are rounded, prominent, with numerous small pores, the base surrounded by a moderately thick collar, and the peristome is con- tinued in a thin ridge above the orifice. The species was described from Taboga Island, Panama, and also listed from Gorgona, Colombia, and the Galapagos Islands. The S. trispinosa of Canu and Bassler, from the Galapagos, at least in part, belongs under crosslandi. Hancock Stations: 24 stations about the Galapagos Islands, with numerous others shorewise northward from Colombia to the Gulf of California. The most northerly record is Station 277, Tiburon Island, 28°43/45”N, 112°15’30’W. It is the commonest species of the genus within this range, from near shore to more than 100 fms. No. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 419 Parasmittina alaskensis new species Plate 48, fig. 13 Zoarium encrusting on a shell, pale yellow, glistening. Zooecia moderate in size, 0.55 to 0.70 mm long by 0.35 to 0.40 mm wide, irregularly ovate, distinct with deep grooves in the young, indistinct with complete calcification. The frontal is a very thick pleurocyst, heavily granulated, a low pointed umbonate process near the aperture; a single row of conspicuous areolar pores with short ribs between them which do not extend upon the front. The primary aperture is nearly round, 0.13 mm wide by 0.12 mm long, straight on the proximal border with a moderate lyrula. The peristome is somewhat elevated all around the aperture, except for a short space on the distal border where there are 2 strong but evanescent spines; cardelles wanting. The secondary aper- ture is ovate in form, usually exposing the lyrula. The avicularia are of two kinds; a round or short-ovate one at or near the proximal end, usually immediately distal to the aperture of the preceding zooecium, with a heavy cross-bar and becoming deeply sunk in the crust in older zooecia; the other type is pointed, with a triangular mandible and elevated rostrum, located a little proximal to the aperture, on one or both sides, the mandible directed toward the aperture. The most striking characters are the heavily and evenly granulated front, the simple ovate secondary aperture and the round, sunken avicu- larium which is usually in the midline at the extreme proximal end. The one colony has no ovicells. Type, U. S. Nat. Mus., 11035. Type locality, Point Barrow, Alaska, 25 fms, Arctic Research Lab- oratory, G. E. MacGinitie, collector. Parasmittina fraseri new species Plate 49, fig. 15 Zoarium encrusting, small, white and glistening, a very attractive little species. The zooecia are rather small, 0.35 to 0.45 mm long by about 0.26 mm wide; alternating in series; younger individuals some- what ventricose and separated by deep grooves, later more nearly flat. Frontal pleurocyst irregularly reticulate over the surface, the areolar pores moderately large with short costae between. Primary aperture small, 0.10 mm wide, rounded, with a very broad lyrula (almost as broad as the aperture) which has a straight border, and with minute cardelles. The lyrula is so hidden by the peristome that it is difficult 420 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 to see. The peristome is thin, a little elevated all around the aperture, more so on the proximal border where two longer points enclose a rounded secondary sinus. Three to five oral spines are present in young stages but soon disappear. Small rounded or elliptical avicularia occur in various positions on the front and occasionally on one or both sides of the peristome opposite the notch, the mandible directed upward on the side of the peristome. On one colony there is a single long-pointed frontal avicularium, the mandible directed laterally. The ovicell is small, about 0.18 mm wide including the secondary border, low and bordered by the pleurocyst of the succeeding zooecium, leaving a rounded frontal area which is finely and regularly porous; the peristome is connected with the sides of the ovicell and in complete calcification forms a low collar around the orifice. Dedicated to the late Dr. C. McLean Fraser of the University of British Columbia. Type, AHF no. 89. Type locality, Station 136-34, Sulphur Bay, Clarion Island, west of Mexico, 18°20/05”N, 114°44’40”W, 32 fathoms. Taken also at Station 23-33, off La Plata Island, Ecuador, 10 fathoms; 155-34, Tagus Cove, Albemarle Island, Galapagos, 50 to 60 fathoms, and 224, Benito Islands, off Lower California. As the colonies are very small and inconspicuous, it may be much more common than the above records indicate. Parasmittina tubulata new species Plate 49, figs. 1-4 Zoarium encrusting, loosely attached, the surface very rough because of the erect tubular peristomes. Zooecia irregularly ovate or quadrate, distinct, large but varying much in size (length 0.70 to 1.00 mm, width 0.40 to 0.60 mm). The front is slightly ventricose, smooth or with small granules; the thin pleurocyst is perforated by a series of small areolar pores and often by a few additional ones. The primary aperture is rounded, 0.16 to 1.18 mm wide, with a moderately long and narrow lyrula (one-fourth as wide as the aperture). Spines wanting. The peristome is extraordinarily high (as much as 0.50 mm), completely surrounding the aperture and with a conspicuous U-shaped or slit-like secondary sinus in the proximal tip; in younger stages the border is smooth, but in complete calcification the rim of the peristome expands slightly and its distal border bears 3 or 4 stout pointed processes; in NO. 2. JSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 421 the fertile zooecia the peristome develops across the front of the ovicell and continues to form an erect tube similar to that of the infertile zooecia. Ihe aperture and lyrula can only be observed on very young zooecia or after dissection. Several types of avicularia are present: 1, small short-spatulate ones on the front, variously situated and oriented; 2, giant broad-spatulate, also on the front, usually directed backward; 3, small pointed or sub- spatulate ones on one or both sides of the peristome; 4, a large pointed one often extending upward on the side of the peristome, the rostrum elevated and pointing at nearly a right angle from the peristomial wall. The ovicell is large, 0.40 mm wide, resting on the succeeding zooe- cium, globular, its base surrounded by a low, smooth collar, the front evenly perforated with small pores; the peristome continues around the border of the orifice without a break to complete the high tube. In certain respects this species appears to be close to S. labellum Canu and Bassler (1928:116) from the Gulf of Mexico, but the great height of the peristomes, the lack of oral spines, the much larger primary aperture and the nature of the peristomial avicularia are sufficient to differentiate it. It has even more resemblance to 8S. projecta Okada and Mawatari (1936:66) from Japan, but the peristomial rim is complete, without oral spines, the peristomial avicularia do not have a serrated rostrum, the areolar pores are inconspicuous, and the ovicell appears to be much larger. Type, AHF no. 90. Type locality, Hancock Station 1978-50, south end of Ranger Bank, west of Lower California, 28°26/45”N, 115°31’30”W, 71 fms. Also Station 1271-41, west of Point Dume, southern California, 34°00’20”N, 119°01’30”"W, 48 fms. Also off Rocky Point, California, 45 fms, Earl Fox, collector. ? Smittia californiensis Robertson, 1908 :303 What this species may be has puzzled me greatly as I am completely unable to interpret Dr. Robertson’s description in terms of any Smittinid species, and unfortunately her types seem to have been lost. She refers to it as common along the California coast from between tide marks to 50 fathoms. Such expressions as: ‘“‘a thick, coarse, spiny crust of a dark gray color’; “primary orifice orbicular, closed by a dark-colored oper- culum’”; and “interspersed between the zooecia are large spatulate avicularia,” certainly do not apply to any local species of the Smittinidae. However, they do apply to Holoporella brunnea Hincks, which she 422 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 does not mention but which is one of the commonest species in the area cited. On the other hand her figure 71 on plate 22 definitely shows a lyrula and peristome of the smittinid type. The genus Holoporella Waters was not established until 1909, a year after Robertson’s paper was published. How so careful an observer could confuse a celleporoid species with the Smittinidae is difficult to understand, but it seems that is what happened as the description is mostly that of H. brunnea and the figure also, with the exception of the lyrula and peristome. The name should be dropped from the literature. Genus CODONELLINA Canu and Bassler, 1934 Codonella Canu and Bassler, 1930:29, preoccupied and changed, 1934: 407, to Codonellina. The ovicell is hyperstomial, closed by the operculum, porous and marginated. The frontal is a tremocyst. A median avicularium is placed before the aperture. The peristome is salient and complete. The aper- ture is suborbicular with a very concave poster; the peristomice bears two false cardelles, limiting a broad rounded sinus (Canu and Bassler). Genotype, Lepralia galeata Busk, 1852. The general appearance is that of a member of the Schizoporellidae, but the delicate nature of the operculum, without sclerites, and the suboral avicularium which communicates with an areolar pore on each side, appear to ally it to the Smittinidae. Codonellina anatina (Canu and Bassler), 1927 Plate 46, figs. 14-15 Codonella anatina Canu and Bassler, 1927 :26. Codonella granulata Canu and Bassler, 1930 :29. Codonella granulata?, Hastings, 1930:725. Zoarium encrusting in a thin, white, shining layer. Zooecia mod- erately large, unusually variable, ranging all the way from 0.45 to 0.90 mm long by 0.26 to 0.45 mm wide, distinct with deep grooves; the frontal is evenly arched, a tremocyst with numerous small pores, smooth but becoming finely granulated in advanced calcification; the aperture rounded or slightly quadrangular, about 0.16 mm in either dimension, a pair of small but distinct cardelles limit a broad shallow poster. The peristome is smooth and somewhat elevated all around the aperture. A small pointed avicularium, directed proximally, is usually present in the midline proximal to the aperture, but it is sometimes asymmetri- NO. Z OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 423 cally located, and it may be replaced by a larger spatulate avicularium, or sometimes wanting. There is much variation in the size and form of the mandible, the tip of the triangular form is sometimes rounded (subspatulate) and the spatulate mandible varies in size and is occa- sionally so narrow as to be almost filiform; the spatulate avicularia may sometimes be half as long as a zooecium. The ovicell is hyperstomial, rounded, 0.26 to 0.30 mm wide and long, with numerous pores and a raised border about the base; the peristome fuses with the ovicell at the sides of the aperture but is not continued across the front. From the data at hand it seems that C. granulata, described from the Galapagos Islands, is synonymous with C. anatina from Hawaii. Canu and Bassler found only the small triangular avicularia on their Galapagos material and among our specimens there are several colonies in this condition. Hastings found spathulate avicularia in her Galapagos specimens and they are present, but not constant, in our material from the Galapagos and the Gulf of Mexico. The measurements are quite variable, transcending in both directions those given for anatina. The giant avicularia of Hawaiian specimens appear to be larger than any from the Galapagos and if this should prove to be a constant feature granulata may be worthy of varietal status. Hancock Stations: dredged at 14 stations among the Galapagos Islands, Albemarle, James, Charles, Hood, Chatham, Albany, Onslow and Wenman Islands; and three stations in the Gulf of California at Angel de la Guardia, Isla Partida and Raza Islands, near 29°N Lat. The known bathymetric range is from 14 to more than 100 fms. Codonellina anatina ligulata new variety This form is rather more distinct than granulata in lacking entirely the small median suboral avicularium. The spatulate avicularia, occa- sionally present, are narrower than those described for anatina, but are of the same general character, about 0.26 mm long, variously located on the front and without any definite orientation, turned sometimes forward, sometimes backward or diagonally. The zooecia are smaller than the usual measurements of the species, length 0.40 to 0.55 mm, the aperture about 0.13 mm in either direction and the ovicell 0.26 mm wide. The other characters agree with typical anatina. Type, AHF no. 91. Type locality, Hancock Station 210-34, Santa Elena Bay, Ecuador, 2°11’25”S, 80°58’W, at 5 to 7 fms, three colonies. 424 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Codonellina cribriformis (O’Donoghue), 1923 Plate 46, fig. 16 Porella cribriformis O’ Donoghue, 1923 :42 ; 1926:72. Codonella cribriformis, Canu and Bassler, 1930 :29. O’Donoghue’s description is good, but incomplete; his figure 30, plate 4, is excellent. Zoarium encrusting. Zooecia moderate in size, 0.50 to 0.65 mm long by 0.30 to 0.40 mm wide, long ovate to hexagonal, somewhat ventricose and very distinct, sometimes with a raised separating line. The frontal is a moderately thick tremocyst with large, regularly spaced pores, shining, hyaline in younger stages, smooth to slightly granular. The aperture is nearly circular, 0.13 by 0.13 mm, with small cardelles between which the broad shallow poster extends, slightly arcu- ated. The operculum is a little chitinized, with a narrow brownish bordering sclerite; muscle attachments near the border. The peristome is thin, moderately elevated all around the aperture, without spines and fusing with the avicularian chamber proximally. ‘The median suboral avicularium is elevated, the mandible usually semicircular but sometimes considerably enlarged and short-spatulate; the avicularian chamber is connected with lateral pores on both sides around the base of the peristome by small tubes to lateral pores, as it is in Porella. The ovicell is hemispherical, partially embedded, a little flattened on the upper surface, with numerous pores which vary in size and form; slightly collared about the base; 0.26 mm wide. Described by O’Donoghue from Departure Bay and listed by him from several other localities in British Columbia and from the San Juan Islands in Puget Sound, 15 to 35 fms. Specimens in the Hancock collections are from Cadboro Bay, British Columbia. Genus RHAMPHOSTOMELLA Lorenz, 1886 Aperture with an asymmetrical poster and a lyrula; frontal an olocyst with costules; a large oblique avicularium excentrically placed below the aperture; ovicell hyperstomial, prominent and closed by the oper- culum. Genotype, R. costata Lorenz, 1886:12. The lyrula is variable in size and wanting in some species; the primary aperture is not always asymmetrical; oral spines are present in at least one species, and frontal avicularia are sometimes present. Most of the species are arctic or at least northern in distribution. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 425 Among the species here dealt with there are two rather distinct subdivisions, based especially on the form of the primary aperture. In the first group, those like the genotype, R. costata Lorenz, there are no cardelles and the proximal border is broadly arcuate (only modified by the median lyrula, when this is present). In general these species are also much more heavily calcified, the costules run up on the front and frontal avicularia are often present. This group includes, besides the genotype, R. scabra (Fabricius), R. fortissima Bidenkap, R. hincksi Nordgaard, R. ovata (Smitt) and R. gigantea Osburn new species. The second group shows a very distinctive bisinuate outline of the proximal border of the primary aperture, with a deep rounded “sinus” on either side between the lyrula and the cardelles, which are usually quite distinct. The frontal is usually plain, the wall is thinner, the costules do not run up on the frontal, and frontal avicularia are wanting. In this group are R. bilaminata (Hincks), R. spinigera Lorenz, R. curvirostrata O’Donoghue, and R. townsendi Osburn new species. Probably R. ovata (Smitt), which has a perforated frontal and an imperforate ovicell should be placed by itself, but R. gigantea also has some additional frontal pores and there is much variation throughout the group. Key To SpEcIEs OF Rhamphostomella 1. Frontal pores present, ovicell imperforate . . . ..... 2 Frontal with areolar pores only, ovicell with pores . . . . . 3 2. Zooecia of moderate size, frontal little granulated . . . . ovata Zooecia very large (over 1 mm long), frontal excessively thick andvrowch Ge 6 Se eet os el car oe Geer Reguganced 3. Lyrula and cardelles both ae Sukh vee yal Be ss 6) HINGES! Lyrula or cardelles or both present . . . chee. ite ee 4. Lyrula and cardelles both present, proximal bodes of primary ApEreWre DISiMMatG’ c) 1s 2. sy ele ee, Oe yen Lyrula present, cardelles wanting . . . - +--+ + +--+ 9 5S) @ral'spimes present... . . . . + + + + + + Spmigera No oral spines . . . ; eo PO 6. Avicularian process high eal HReibes eat a ities peristomial lappet opposite . < . +» «© - « «1% «© « « Otlaminata No flabellate process opposite the ay ealarium fe tok. Re aa ae 7. Avicularian rostrum and mandible curved nA across the aperture 5 C : : . . curvirostrata Rostrum and eoainle eee ek not iste over the aperture 8 426 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 8. Avicularium large and prominent . . . ~ eo) towntsends Avicularium very small, conforming to ie margin of the peri- Stomes |) 5. 4: en ere MPR OM mer 6 GRU a 9. Numerous giant oes eee eR Lewis . . fortissima Frontal avicularia, when present, smaller; a Heh pointed umbo with costal. ridges) 4.1) 20 Be Ae eee Rhamphostomella costata Lorenz, 1886 Plate 50, fig. 7 Rhamphostomella costata Lorenz, 1886 :12. Rhamphostomella costata, Nordgaard, 1906 :30. Rhamphostomella costata, Osburn, 1912 :244; 1919 :610. Rhamphostomella costata, O’Donoghue, 1923 :44; 1926:72. Encrusting, usually on stems and rising into flabellate bilaminate expansions or contorted folds. The zooecia are large, 0.60 to 0.90 mm long by 0.40 to 0.50 mm wide; distinct, the frontal arched and rising into a high pointed umbonate process on the top of the avicularian chamber which covers practically all of the width of the front; there is a row of large areolar pores, between which strong costal bars run up even to the tip of the umbonate process. This process is higher than in the other species of the genus, a little asymmetrical in position, and its tip is often developed into a transverse bar (variety cristata Hincks). The primary aperture is round distally, the proximal border somewhat straighter and a little asymmetrical, without cardelles, but with a small lyrula which is often wanting. The secondary aperture is usually a little angulated proximally, due to the overhanging base of the umbonate process. A moderately large avicularium, with a subspatulate mandible is located at the side of the base of the process and directed vertically. Frontal avicularia with a triangular mandible are found on most of the zoaria, located near the proximal end of the zooecia. The ovicell is large, about 0.40 mm wide, prominent, perforated with large pores, more or less submerged by advanced calcification. A common arctic and northern species, extending down the Atlantic coast to Cape Cod, Massachusetts, and on the Pacific coast to Puget Sound. Recorded by O’Donoghue from a number of British Columbia localities. Point Barrow, Alaska, down to 23 fms, G. E. MacGinitie, collector (Arctic Research Laboratory). Also from Friday Harbor, San Juan Island, Puget Sound, Dr. J. L. Mohr, collector. NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 427 Rhamphostomella fortissima Bidenkap, 1900 Plate 50, figs. 1-2 Rhamphostomella fortissima Bidenkap, 1900 :524. Discopora scabra var. fortissima, Nordgaard, 1918:78. This species bears a close resemblance to R. costata in the younger stages and the measurements are close, though in our specimens the primary aperture is somewhat larger (about 0.26 mm in either dimen- sion). Possibly Nordgaard is correct in giving it merely varietal status, but in our specimens the costae do not extend beyond the base of the umbo, the secondary calcification is much heavier, and raised frontal avicularia of huge proportions are abundantly distributed over the surface. Recorded by Bidenkap and Nordgaard from Spitsbergen and several of the northern fjords of Norway. Point Barrow, Alaska, 23 fms, Arctic Research Laboratory, Prof. G. E. MacGinitie, collector, several colonies. Rhamphostomella bilaminata (Hincks), 1877 Plate 52, fig. 10 Cellepora bilaminata Hincks, 1877 :111. Rhamphostomella bilaminata, Lorenz, 1886 :13. Discopora bilaminata, Levinsen, 1916 :461. Rhamphostomella bilaminata, Osburn, 1923:10D. Rhamphostomella porosa, O’ Donoghue, 1923 :45. Zoarium encrusting on various surfaces, frequently on hydroid stems where they rise into bilaminate folds. Zooecia of moderate size, 0.65 to 0.75 mm long by 0.40 to 0.45 mm wide; the front nearly flat, smooth or with short costae which do not run to the base of the umbonate process, areolar pores large but indistinct because of the crowding together of the zooecia. The primary aperture is rounded, about 0.20 mm in either dimension, the proximal border bisinuate with a small cardelle at each side and a bifurcate lyrula in the midline, deeply immersed within the peristome. On the proximal border there is a moderate-sized avicularian chamber, asymmetrically located, the rostrum high and lobed; a spatulate mandible; opposite this is a high peristomial lappet of similar form, the two producing a large slit-like sinus in the secondary aperture. The ovicells at first are hemispherical and prominent, about 0.40 mm wide, with large pores, but with advancing calcification they become almost completely immersed. 428 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 It is a common arctic and northern species, occurring on the Atlantic coast as far south as Cape Cod, Massachusetts; abundant in the waters about Greenland, and recorded as far west as Icy Cape, Alaska (Osburn, Canadian Arctic Exped.). It has not been reported south of Alaska, except for O’Donoghue’s record of R. porosa at Cape Ebenshaw, British Columbia. O’Donoghue recognized the similarity to bilaminata, but the distinguishing characters which he indicates for porosa (viz., “the far larger size of the rostrum and peristome’’) are within the range of variation of bilaminata. U. S. Alaska Crab Investigation, Leonard Harbor, Alaska, station 60-40, at 25 fms; also at Point Barrow, Alaska, Arctic Research Labora- tory, down to 23 fms. G. E. MacGinitie, collector. Rhamphostomella hincksi Nordgaard, 1906 Plate 50, fig. 3 Rhamphostomella hincksi Nordgaard, 1906:31. Cellepora plicata, Hincks, 1877 :106. Zoarium encrusting on various surfaces. Zooecia moderately large, 0.70 to 0.85 mm long by 0.45 to 0.55 mm wide: frontal somewhat inflated, smooth, with a row of conspicuous areolar pores between which costal ribs run up for a short distance on the front (occasionally to the base of the rostrum) as noted by Hincks and Nordgaard. The primary aperture is nearly round, about 0.26 mm in either dimension, a little narrower and slightly asymmetrical proximally, and without either cardelles or lyrula (as noted by Nordgaard). Proximal to the aperture and asymmetrically placed is a moderate-sized bulbous avicu- larian chamber, the rostrum high and extending somewhat over the aperture; the distal wall of the rostrum is nearly straight and set at an angle to the midline and a peristomial lappet is directed in the same manner on the opposite side so that the secondary aperture is angulated proximally (a condition which no doubt led Hincks to place this species under R. plicata). The mandible is short-spatulate or a little narrowed terminally. The ovicell is large, 0.35 to 0.40 mm wide and 0.30 to 0.35 mm long, prominent, smooth or roughened around the sides, with several frontal pores and the area above the orifice a little flattened. The complete absence of lyrula and cardelles seems to ally this species with R. scabra (Fabricius) rather than R. flicata (Smitt). No. 2. OSBURN: EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 429 Recorded by Nordgaard from several places in the Greenland area, and from Iceland by Hincks. Point Barrow, Alaska, 25 fms, Arctic Research Laboratory, G. E. MacGinitie, collector. Also a specimen from Tuan Island, Pavlof Bay, Alaska. Rhamphostomella spinigera Lorenz, 1886 Plate 51, fig. 1 Rhamphostomella spinigera Lorenz, 1886 :12. Rhamphostomella spinigera, Nordgaard, 1906 :32. Discopora plicata var. spinigera, Levinsen, 1916 :460. Rhamphostomella spinigera, Osburn, 1936 :542. Zoarium encrusting. Zooecia moderate in size, 0.60 to 0.70 mm long by about 0.40 mm wide, distinct with deep separating grooves; the front somewhat inflated, smooth with delicate reticulations, with a row of areolar pores between which short costae reach only to the edge of the frontal wall. The primary aperture is rounded, 0.22 mm wide by 0.20 long, the proximal border bisinuate, with a cardelle at each end and a median lyrula which is usually expanded at the tip. The peristome is thin, elevated into a lappet opposite the avicularian umbo, and with about 4 oral spines which are rather evanescent. The avicularian chamber is moderate in size and rarely extends past the midline of the front, the rostrum narrow and high and bearing on its lateral surface an elongate avicularium with a spatulate mandible. Opposite the rostrum is a small lappet of the peristome and the form of the secondary aperture is more or less angulated proximally and rounded distally. The ovicell is hemispherical and conspicuous, often slightly longer than wide (0.30 mm wide by 0.30 to 0.35 mm long), with small pores. One pair of oral spines is often involved in the proximal corners of the ooecium. Described from Jan Mayen, and listed by Nordgaard, Levinsen and Osburn from Greenland. Canoe Bay, Alaska, U. S. Alaska Crab Investigation, Sta. C. 160-41, 28 fms; and Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector, 18 fms. 430 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Rhamphostomella curvirostrata O’Donoghue, 1923 Plate 50, fig. 4 Rhamphostomella curvirostrata O’ Donoghue, 1923 :44. Zoarium encrusting in a thin layer. The zooecia are moderately large, 0.75 to 0.85 mm long by 0.40 to 0.55 mm wide, the front evenly arched, undecorated except for fine granulation, with a row of large areolar pores; the costae separating the pores do not extend upon the front. There is often a raised line in the groove separating the zooecia. The primary aperture is nearly round, the proximal border bisinuate with a small cardelle at each side and a lyrula of varying width (notched at the tip) in the middle ; 0.24 mm wide by 0.22 mm long. The peristome is thin, high and tubular, continued around the aperture except for a notch at the middle of the distal border; at one side of the proximal border is an elevated avicularian chamber, with a long, laterally curved rostrum which extends more or less across the proximal part of the aperture and which may fuse with a prominent lappet on the opposite side to enclose the proximal part of the secondary aperture. The mandible is elongate-triangular, curved laterally and hooked at the tip. Occasion- ally the avicularium is wanting and two lateral lappets extend toward each other across the aperture. The ovicell is hemispherical and prominent, about 0.40 mm wide by 0.35 mm long, smooth, with numerous pores. The most striking characters of this species are the high peristome and the curved and elevated avicularium which partially or entirely subdivides the secondary aperture. Described by O’Donoghue from Bull Passage, Northumberland Channel, British Columbia, 15 to 25 fms. Hancock Station 1662-48, Santa Cruz Island, southern California, numerous colonies at 23 fms. Also on a sunken buoy recovered from 45 fms off Rocky Point, California, Earl Fox, collector; and San Juan Island, Friday Harbor, Puget Sound, Dr. J. L. Mohr, collector. Rhamphostomella townsendi new species Plate 51, figs. 2-3 Zoarium encrusting on sponge. The zooecia are large, 0.85 to 1.15 mm long by 0.50 to 0.60 mm in width; the frontal rather evenly in- flated and beautifully reticulate with honeycomb impressions, with con- spicuous areolar pores between which the short costae extend only slightly ; a prominent line in the deep separating grooves. The primary aperture is nearly symmetrical, rounded, with a pair of pointed cardelles NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 431 and a small bicuspidate lyrula; the peristome is high and thin and unites slightly with the proximal corners of the ovicell. ‘The secondary aperture is asymmetrically ovate. Proximal to the aperture and asymmetrically placed is a comparatively small avicularium with the long-triangular mandible directed more or less laterally; the avicularian chamber only slightly elevated. The ovicell is prominent, hemispherical, smooth with large pores and with a low collar around the base; 0.40 mm wide by 0.25 to 0.30 mm long. This is a striking species, due to its smooth appearance, as the only decoration of the front is the delicate reticulation. aype, U.S. Nat: Mius:, 11032. Type locality, Albatross Station 5695 (cruise of 1911), Lower Cali- fornia, 534 fms. It is named in memory of my former friend, Dr. Charles Haskins Townsend, Naturalist on the “Albatross” from 1886 to 1896 and tem- porarily on the cruise in 1911 when this species was dredged. Rhamphostomella cellata (O’Donoghue), 1923 Plate 52, fig. 9 Smittia cellata O’Donoghue, 1923 :43. Smittina cellata, O’ Donoghue, 1926 :68. Smittia torquata O’ Donoghue, 1923 :43. Smittina torquata, O’ Donoghue, 1926 :68. Zoarium encrusting, smooth and glistening. The zooecia are moder- ately large, 0.65 to 0.90 mm long by 0.45 to 0.55 mm wide, ovate, slightly inflated ; the frontal thin and smooth, later becoming granulated, a row of areolar pores separated by short costules ; a crescentic area proxi- mal to the aperture is delicately outlined. The aperture is nearly round, about 0.18 to 0.20 mm in either direction; the cardelles distinct and pointed and there is a slender bifid lyrula with laterally directed points. The peristome is thin and more or less elevated, connected with the avicularian chamber on one side and forming a low lappet on the oppo- site side. The avicularian chamber is small and low, asymmetrical and connected with one areolar pore, the mandible is long-triangular and directed laterally; when completely developed the mandible appears as if lodged just within the rim of the peristome and curved to conform to it. 432 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 The ovicell, according to O’Donoghue’s description and figure is characteristic of the genus, ‘“‘globose, hemispherical and projecting, and its surface perforated by a series of large irregular pores.” There can be no question as to the position of this species in the genus Rhamphostomella. Similarly I have no doubt that Szittia tor- quata O’ Donoghue is merely the young stage of his S. cellata as the basic characters are the same and the only differences are due to advanced calcification and the presence of the ovicell. Described from British Columbia and recorded from numerous lo- calities there and about the San Juan Islands in Puget Sound. Dr. J. L. Mohr collected the species for the Hancock collections at Middle Bank, Puget Sound. Rhamphostomella ovata (Smitt), 1867 Plate 50, fig. 6 Cellepora ovata Smitt, 1867:31. Rhamphostomella ovata, Nordgaard, 1906 :32. Rhamphostomella ovata, Osburn, 1912 :248; 1919 :610. Discopora ovata, Nordgaard, 1918:78. Zoarium encrusting on stones and shells, occasionally on stems. The zooecia are smaller than those of our other species, averaging about 0.70 mm long by 0.45 mm wide, elongate oval, regularly arranged in quin- cunx; the front is evenly arched, with a number of large pores in addition to the areolar pores, the costae if present short and not prom- inent. The avicularian chamber is comparatively small, usually reaching only to the midline; the umbonate process small and low, consisting chiefly of the avicularian rostrum which bears on its lateral face a small elliptical avicularium with a round-tipped mandible. The primary aperture is rounded, 0.28 to 0.30 mm long and wide, the proximal border often a little asymmetrical. ‘There are no cardelles and in our specimens no lyrulae; rarely vestigial oral spines on very young zooecia. (Nordgaard, 1906:34, lists this species among those which have a “median denticle,’” but I have never found it in all the Atlantic and arctic specimens I have seen.) The secondary aperture is more or less asymmetrically ovate, the slightly overhanging base of the avicularium producing a straighter edge at that side. The ovicell hemispherical, prominent, smooth and imperforate when young, but becomes rough when covered by secondary calcification. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 433 This species is unique in the genus in view of its perforated frontal and imperforate ovicell but, as all other characters agree and no other genus appears to fit it, I leave it where it has usually been assigned. It is fairly common in the arctic and northern seas, extending southward on the Atlantic coast to Cape Cod, Massachusetts. It seems not to have been noted on the Pacific coast. Alaska Crab Investigation, entrance to Olga Bay, 40 fms and Leon- ard Harbor, 25 fms, Alaska; Punuk Island, Bering Sea, 15 fms; and Point Barrow, Alaska, 23 fms, Arctic Research Laboratory, G. E. Mac- Ginitie, collector. Rhamphostomella gigantea new species Plate 50, fig. 5 Zoarium encrusting and forming coarse, erect, bilaminate expansions and frills to a height of 25 to 40 mm, yellowish to deep orange in color. The zooecia are among the largest I have ever observed, averaging 1.20 mm long (ranging from 1.00 to 1.80 mm), the width ranging from 0.65 to 0.80 mm; the depth is correspondingly great, the cavity varying from 0.60 to 0.75 mm and the total thickness about 1.00 mm in full calcification. The frontal is highly arched and excessively thick, with a row of large areolar pores and a varying number of frontal pores; very strongly costate, the costae often uniting to form a coarsely reticulate surface over the whole front; the ribs sometimes extend to the tip of the avicularian umbo. The avicularium arises at one side but its base is so broad that it often covers nearly the whole width of the frontal; the avicularium is located on the disto-lateral side of a low-conical umbonate process, the mandible slightly more than a semicircle in form, about 0.13 mm long and wide. The primary aperture is only slightly asymmet- rical on its proximal border, rounded distally and somewhat straighter on the sides, the length and breadth nearly equal, 0.40 to 0.45 mm. The peristome is moderately low on the sides. No oral spines, no cardelles and no lyrula. Small oval avicularia, similar in size and form to the suboral ones, often occupy the middle of the frontal, mounted on a slightly elevated chamber. The ovicells are proportionate in size to the zooecia, averaging about 0.65 mm wide by 0.50 mm long, smooth and imperforate, prominent when young but with complete calcification almost entirely immersed. Type, U. S. Nat. Mus., 11033; paratype, AHF no. 93. Type locality, Point Barrow, Alaska, Arctic Research Laboratory, 140 feet, Prof. G. E. MacGinitie, collector. Another colony at a depth of 80 feet from the same locality. 434 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 Genus CYSTISELLA Canu and Bassler, 1917 Zoarium erect, branching, flabelliform, bilaminate. The frontal is an olocyst with few areolar pores; a large elongate avicularium chamber covers most of the front, with two large pores in its proximal end a little distal to the preceding aperture, and its mandible is semicircular and perpendicular to the apertural plane. No lyrula, no oral spines, cardelles present. Ovicell hemispherical, smooth and imperforate. Genotype, Es- chara saccata Busk, 1856. A short, broad lyrula is present in some species. The avicularian chamber is unique in that it extends the full length of the front of the zooecium, originating from proximal instead of lateral pores. Cystisella saccata (Busk), 1856 Plate 51, figs. 4-5 Eschara saccata Busk, 1856 :33. Cystisella saccata, Osburn, 1923 :10D. A common high northern species, growing in erect bilaminate folds to a height of 50 mm. The zooecia are moderately large, averaging about 0.75 mm long, quincuncial in arrangement, the frontal thick, smooth and shining, with one or two pores at the proximal end (visible only after removal of the ectocyst). Most of the front is covered by a large and elongate avicularian chamber which extends from the proximal pores to overhang the aperture; the distal end is vertical to the plane of the aperture and is occupied by a large semicircular mandible. The primary aperture is so deeply hidden below the avicularium and the high peristome that it can be seen only on young zooecia; it is a little more than a semicircle, with a straight proximal border and without lyrula or cardelles; 0.18 to 0.20 mm wide. The ovicells in the young stage are globular, prominent, smooth except for faint radiating striae but in older parts of the colony they become embedded and covered by the thick crust; width and length 0.30 to 0.35 mm. This species was confused for many years with C. elegantula (d’Or- bigny) until Waters, 1900:81, pointed out the differences. It is widely distributed in the arctic region and Osburn (1923, Canadian Arctic Exped.) recorded it as far west as Icy Cape, Alaska. Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic Research Laboratory. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—-CHEILOSTOMATA 435 Cystisella bicornis new species Plate 51, figs. 6-7 Zoarium erect from a small encrusting base, flabellate, reaching a height, in our specimens, of 10 mm, bilaminate. Zooecia moderate in size (0.55 to 0.65 mm long), arranged in quincunx, the frontal smooth with the usual two pores at the proximal end. As in other species of the genus, the frontal is largely covered by the elongate avicularian cham- ber, but the distal end is more erected than in C. saccata and the position of the avicularium is less vertical: the mandible is usually slightly tri- angular or ogival, but is sometimes nearly semicircular, yellow and heavily chitinized and with the tip decurved. On either side of the mandible between it and the corner of the aperture is a short, stout conical process which often projects well above the level of the avicula- rian rostrum; there is much variation in these spinous processes, near the base of the colony they are absent, in younger colonies they are smaller and shorter, in older zoaria they are regularly present except near the base. The primary aperture (seen only at the zoarial edge) is somewhat more than a semicircle, the sides and the proximal border straight ; no cardelles and no lyrula; width and length 0.15 to 0.16 mm. The ovicell is like that of saccata but smaller, 0.26 mm, round, prominent, smooth and delicately striated when young, but becoming completely embedded with age. The species differs from C. saccata in its more erected avicularia, the form of the mandible, the presence of the spinous processes, and in the smaller measurements of the aperture, ovicell and zooecia. Type, U. S. Nat. Mus., 11031; paratype, AHF no. 94. Type locality: Point Barrow, Alaska, Arctic Research Laboratory, 7 to 25 fms, Prof. G. E. MacGinitie, collector, 7 colonies. Also from Orca, Prince William Sound, Alaska, without further data, 3 colonies, and the Dall collection from Alaska, 1 colony. Genus MUCRONELLA Hincks, 1880 Hincks’ description indicates merely ‘“Zooecia with a subcircular or semicircular orifice; the peristome elevated in front into a more or less prominent mucro,” but later he states “the lower margin of the orifice is almost universally dentate” (that is, with a lyrula). However, the first three species discussed by him are characteristic, and the first men- tioned, Lepralia peachii Johnston (—L. immersa Johnston), is the genotype. 436 ALLAN HANCOCK PACIFIC EXPEDITIONS VoL. 14 The frontal is a pleurocyst, with one row (occasionally 2 or 3) of areolar pores. Spines are present on the oral border. No avicularia. The lyrulae are like those of S7nittina, varying in length, breadth, exca- vation of the tip and in the lateral points. Dietellae are present and sometimes characteristic of species. Key To SpEcIEs OF Mucronella 1. Peristome high, tubular, oral spines 8 to 10 . . . . . major Peristome not tubular but forming an umbonate PFOCESS Spines 2. {GO Oe «ee ca Lae ee « » OCs ee 2. Dietellae long, only two on a side; ovicell a a raised lip above the orifice . . . . , . . €onnectens Dietellae small and numerous; ovicell ieee a lip.) 3) eee 3. Front highly arched transversely ; zooecia more elevated distally ; ovicell high and depressed toward the tip . . Jabiata Front moderately arched: distal end of zooecium not unusually elevated; ovicell broadly rounded . . . ventricosa Mucronella ventricosa (Hassall), 1842 Plate 52, fig. 3 Mucronella ventricosa, Hincks, 1880 :363. Mucronella ventricosa, Osburn, 1912 :243. Mucronella ventricosa, O’ Donoghue, 1923 :46; 1926:70. Zoarium encrusting, usually on shells and stones. Zooecia mode- rately large, averaging about 0.75 mm long by 0.45 mm wide, more or less ovate but varying widely in proportions; very distinct even in full calcification, with deep grooves. ‘The front is ventricose, delicately pebbled with minute tubercles which are usually arranged in radiating lines; numerous small areolar pores usually in one row but occasionally two. The primary aperture, 0.16 mm wide by 0.13 mm long, is straight on the proximal border, with a moderately broad lyrula. The peristome is thin and little raised on the sides and bears 6 to 8 long erect spines; proximal to the aperture it is raised into a thick fold which usually is continued into a pointed umbonate process overhanging the aperture more or less. Ovicell subglobose and prominent, slightly immersed in full calcifi- cation, 0.35 mm wide by 0.30 mm long, imperforate, the secondary cover finely pebbled like the frontal. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 437 An abundant northern and arctic species, extending down the At- lantic coast to Cape Cod, Massachusetts, and on the Pacific coast to Oregon. O'Donoghue recorded it from a number of localities in British Columbia. Hancock collections. Not taken in the Hancock dredgings, but there are specimens from the “Albatross” Sta. D.2886, off the Oregon coast; Puget Sound, Dr. J. L. Mohr, collector, and Point Barrow, Alaska, Arctic Research Laboratory, G. E. MacGinitie, collector. Mucronella connectens (Ridley), 1881 Plate 52, figs. 6-7 Mucronella ventricosa var. connectens, Ridley, 1881 :451. Escharella indivisa Levinsen, 1916 :450. Mucronella indivisa, Osburn, 1932 :14. Mucronella connectens, Osburn, 1936 :542. This species has much the appearance of M. ventricosa, with which Ridley associated it. On closer study it shows a number of differences which are sufficient to distinguish it clearly. The size of the zooecia is larger, length 0.75 to 0.95 mm, the lyrula is a broad shelf, extending nearly the full width of the proximal border of the aperture, the peri- stome proximally is high and thin, extended into a low point and de- scending on the sides to the base of the spines (2 to 4 in number) ; the aperture is somewhat larger, 0.18 to 0.20 mm wide by 0.14 long; and the ovicell has a different form, narrow proximally, widest at its middle and with a distinct raised lip above the orifice. “The most distinctive feature is the very elongate pore chambers (dietellae) limited to usually two on each side, whereas in ventricosa they are small and numerous. Ridley described the species from Spitsbergen and figured it care- fully, showing the long dietellae. Levinsen redescribed it as indivisa from Greenland, apparently overlooking Ridley’s description. Osburn had it (M. indivisa) from Hudson Strait and Port Burwell, Ungava, and again from Greenland (M. connectens). Point Barrow, Alaska, not uncommon on stones at 18 to 26 fms, Arctic Research Laboratory, G. E. MacGinitie, collector. Mucronella labiata (Boeck MS), Levinsen, 1886 Plate 52, figs. 1-2 Lepralia labiata Boeck, MS. Discopora coccinea form labiata, Smitt, 1867 :27. Mucronella labiata, Levinsen, 1886 :19. 438 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 Escharella labiata, Levinsen, 1916:451. Escharella labiata, Nordgaard, 1918:55. Zoarium encrusting on stones and shells. The zooecia are large, 0.75 to 0.90 mm long by 0.40 to 0.50 mm wide, highly arched and elevated distally, very distinct; the frontal densely and minutely gran- ulated, with 1 to 3 rows of small lateral pores. The primary aperture is semicircular, 0.18 to 0.20 mm wide, the proximal border straight with a broad, short lyrula. ‘The peristome is high proximally, extending almost vertically into a rounded or pointed process, descending sharply on the sides to the oral spines; in the presence of an ovicell it fuses around the spines with the ooecial cover. The spines are strong and erect or somewhat bent over the aperture, 1 pair. The ovicell is large, 0.30 to 0.35 mm wide by about 0.30 mm long, more or less hemispherical and the distal end is often sloped downward toward the base of the succeeding zooecium. It has been recorded from numerous localities from the Kara Sea to Greenland, but has not hitherto been known from the Pacific area of the Arctic Ocean. It is undoubtedly another circumpolar species. Point Barrow, Alaska, 18 fms, G. E. MacGinitie, collector, Arctic Research Laboratory. Mucronella major (Hincks) 1884 Plate 52, figs. 4-5 Mucronella spinosissima form major Hincks, 1884:53. Phylactella major, Canu and Bassler, 1923 :170. ?Mucronella microstoma, O’Donoghue, 1923 :46. ?Mucronella simplicissima var. perforata O’Donoghue, 1923 :46. Zoarium encrusting on stones, shells and stems, forming white irregular colonies. ‘The zooecia are moderately large, 0.60 to 0.75 mm long by 0.40 to 0.50 mm wide, varying greatly in proportions, sometimes nearly as broad as long and again elongate and lageniform, apparently in response to the substratum; very distinct and separated by deep grooves. The ventricose front is a smooth pleurocyst with 2 or 3 rows of small marginal pores; as the pleurocyst develops inward from the margin the pores are carried along as microscopic tubules as far as to the middle of the front and even up along the sides of the peristome and over the top of the ovicell. When the process of calcification is com- plete the front and the ovicell have the appearance of a tremocyst. Hincks described these as ‘‘slender tubes immersed in the cell wall”; they are very clear in the younger zooecia but may be completely ob- NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 439 scured with age. The primary aperture is about 0.11 to 0.13 mm wide by 0.10 mm long, rounded, the proximal border straighter with a moderately broad lyrula which has a lateral point at each corner. The primary peristome is low and bears a series of 8 or 10 long, slender vertical spines; the secondary peristome begins as an umbonate process proximal to the aperture and develops into a tube of varying height (occasionally as much as 0.40 mm), formed by the pleurocyst which usually fuses with the spines and often carries a series of the areolar tubules with it up on the sides. The tips of the spines may often be seen projecting above the partially developed peristome. ‘The fully de- veloped peristome also usually bears a small proximal denticle projecting inward from the tip of the tube. No avicularia. The dietellae are small and numerous. The ovicell is semiglobular, smooth, imperforate, recumbent, resting on the succeeding zooecium, the pleurocyst of which grows up over it, carrying the small tubules with it; in complete calcification it appears, like the frontal, to be covered by a tremocyst. Hincks described it from British Columbia, ‘‘probably the commonest species amongst Dr. Dawson’s dredgings.’’ Canu and Bassler listed it from the Pleistocene of Santa Monica, California, under the genus Phylactella; in complete calcification there is much resemblance to that genus, but the supposed frontal pores are merely the ends of the areolar tubules distributed through the pleurocyst. Our abundant material represents all stages of the development. O’Donoghue did not recognize it, but I am of the opinion that his record of M. microstoma belongs here, and that his M. simplicissima var. perforata, “with scattered per- forations” is the complete stage of development of the same species. Hancock Stations: taken at 10 stations about the islands off southern California; at Point San Eugenio and San Juanico Bay, Lower Cali- fornia; at Clarion Island, west of Mexico; and at three stations, Charles, Albemarle and James Islands, Galapagos. This temperature range is very wide, but there are numerous other species with a similar range. The known bathymetric range is from shallow water down to 135 fms. Genus HEMICYCLOPORA Norman, 1894 “Zooecia with pores confined to the sides and sometimes anterior portion of the front wall. Mouth-opening well arched above, lower margin straight (no denticle within the lip). Reproduction by ooecia, which are imperforated. No avicularia.” Norman. Genotype, Lepralia polita Norman. 440 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 As Norman remarks, “This genus comes very near to Mucronella, but differs in the absence of the denticle (“lyrula’).” In addition, the frontal slopes downward and thins out at the proximal! border of the aperture and there is no suggestion of the mucro which is characteristic of Mucronella. Otherwise the two genera appear to agree in all details. Hemicyclopora polita (Norman), 1864 Plate 52, fig. 8 Lepralia polita Norman, 1864 :87. Discopora emucronata Smitt, 1871:1129. Lepralia polita, Hincks, 1880:315. Hemicyclopora polita Norman, 1894:124. Encrusting stones in a smooth reddish or yellowish-brown layer. ‘The zooecia are large, ranging from 0.75 to 1.00 mm long by 0.50 to 0.75 mm wide, very distinct with deep separating grooves; the frontal con- siderably inflated, smooth (only in extreme calcification the surface is minutely granulated), with 1 or 2 rows of areolar pores. The primary aperture is large, 0.18 mm wide by 0.15 mm long, the sides straight for a short distance and the proximal border usually quite straight; there is no lyrula or at most a very slight irregularity near the middle of the border. The peristome is slightly raised on the lateral and distal borders, provided with 6 (rarely 8) strong erect spines; on the proximal border the peristome is entirely wanting and there is no evidence of an umbonate process or mucro. No avicularia. The dietellae vary from small to moderately elongate. The ovicell is large, 0.40 to 0.45 mm wide by 0.35 to 0.40 mm long, hemispherical and prominent, smooth and shining like the frontal: the proximal pair of spines are fused in the proximal corners of the ovicell. ‘The species was described by Norman from the Shetland Islands at 70-100 fms, and later recorded by him from the Hebrides and Green- land, and from the Trondhjem Fjord, Norway. Smitt evidently over- looked Norman’s description and redescribed it from Spitsbergen as Discopora emucronata. Point Barrow, Alaska, 18 to 26 fms, Arctic Research Laboratory, Prof. G. E. MacGinitie, collector, abundant. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 441 Family Adeonidae Jullien, 1903 The frontal is a thick pleurocyst; the areolae are unique in that they do not open directly through the frontal wall but proceed downward in the lateral wall to communicate with the septulae. In some genera there is an ascopore which may be near the center of the front wall, but in other genera the compensatrix opens in the sinus of the aperture. “The fertile zooecia are gonozooecia which are usually larger and provided with a larger aperture. Both frontal and interzooecial avicularia may be present. Genus ADEONA Lamouroux, 1812 Zoarium encrusting. Frontal wall a thick pleurocyst, with an asco- pore in the center; tubular areolar pores; primary aperture at the bottom of a peristomial tube. Ovicells endozooecial on gonozooecia which are usually larger than ordinary zooecia and without a peristome. Geno- type, ddeona grisea Lamouroux, 1816. Adeona violacea (Johnston), 1847 Plate 58, figs. 6-7 Lepralia violacea Johnston, 1849 :325. Porina violacea, Smitt, 1873 :30. Microporella violacea, Hincks, 1880 :216. Adeona violacea, Osburn, 1914:199; 1940 :445. Adeona plagiopora, Canu and Bassler, 1928 :126. Adeona violacea, Hastings, 1930 :728. Zoarium encrusting, often forming rounded nodules, ranging in color from lavender to intense purplish-black. “The zooecia are moderate in size, 0.40 to 0.55 mm long, 0.25 to 0.30 mm wide, the frontal somewhat ventricose, the pleurocyst thick and roughened with a row of conspicuous areolar pores. At or near the center is an ascopore which, with the thick- ening of the front, lies at the bottom of a rounded indentation. An avicularium with a pointed mandible is situated between the ascopore and the aperture and directed distally in the midline (directed more or less laterally in the variety plagiopora). The primary aperture is small, transversely short-elliptical, averaging about 0.12 mm wide by 0.09 mm long; there is a short-tubular peristome. No spines. The gonozooecia are slightly larger than the infertile zooecia and the aperture measures about 0.15 mm wide. 442 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 It is a conspicuous species because of its color, distributed around the world in warmer waters; on the Pacific coast noted only by Hastings at Gorgona, Colombia, and Mazatlan, Mexico. Hancock Stations: a common species dredged at 24 stations; from San Benito Islands off the west coast of Lower California and Angel de la Guardia Island in the Gulf of California, to the Galapagos Islands; including Clarion and Socorro Islands west of Mexico; the coast of Mexico; Cocos Island off Costa Rica; Secas Islands and Taboga Island, Panama; Octavia Rocks, Colombia; and the Galapagos Islands. The range is therefore from about 28’N southward to the equator, and from the shoreline down to 125 fms. Adeona tubulifera Canu and Bassler, 1930 Plate 58, fig. 8 Adeona tubulifera Canu and Bassler, 1930 :34. This species differs from 4. violacea (Johnston) in the larger size (average 0.65 mm long by 0.45 mm wide), in the presence of a tall, thick-walled peristome, and the location of the avicularium on the proximal wall of the peristome instead of on the frontal. Our specimens encrust coralline nodules and are coarser in appearance than violacea, and I have never observed any pigmentation. “The ascopore and the aperture are similar to those of violacea, but the avicularium is much more slender and is pointed upward on the peristome above its base. The gonozooecium has no peristome, is noticeably enlarged, and its aperture measures 0.18 mm in width. Known only from the Galapagos Islands, “Albatross” stations D.2813 and D.2815. Hancock Stations, 143-34, Wenman Island; 147-43 and 155-34, Albemarle Island; 170-34, and 438, Chatham Island; 810-38, Barring- ton Island: 409, James Island; 469, Charles Island: and 473, Hood Island, all from the Galapagos. Also at 210-34, Santa Elena Bay, Ecuador. The known range is very limited and near the equator, and bathymetrically from 10 to more than 100 fms. Genus TRIGONOPORA Maplestone, 1902 Metrarabdotos Canu, 1914. ““The ovicell is endozooecial. ‘The aperture is semilunar, with a rimule and lyrula. The frontal is surrounded with lateral areolae and formed of an olocyst surmounted by a pleurocyst’? (Canu and Bassler, 1920 :533). Genotype, Trigonopora vermicularis Maplestone, 1902 :23. NO. 2. OSBURN: EASTERN PACIFIC BRYOZOA—CHEILOSTOMATA 443 The ovicell is very large, broader than a zooecium, and the fertile zooecium has a long transverse aperture that contrasts sharply with the apertures of the ordinary zooecia. “Triangular avicularia are often present at the side of the aperture. Trigonopora pacifica new species Plate 58, fig. 9 Zoarium encrusting, covering large areas on shells; dark reddish brown or purple, due to the pigmentation of the thick ectocyst which covers the whole surface except the aperture and the avicularia. “The dorsal wall is thin and smooth. Zooecia moderately large, length 0.65 (0.50 to 0.75) mm, width 0.35 to 0.45 mm; quadrangular or somewhat ovate; little ventricose; the whole surface to the edge of the peristome covered with a thick smooth ectocyst, beneath which is the roughly granular pleurocyst per- forated at the edges by a row of large areolar pores, which are separated by short costae. The peristome is somewhat elevated, thin, rounded or short-ovate, with a deep, narrow proximal sinus, but without the “lyrula.” The primary aperture is nearly circular, about 0.15 mm in diameter, without a sinus but the peristomial sinus (rimule spiramen) rises immediately above it. The avicularia, which are not abundant, are located at one or both sides of the peristome, directed forward and inward and the tip of the mandible curved outward slightly; the mandible is shorter and less curved than in the Atlantic species (T. unguiculata Canu and Bassler 1928 :128). The ovicell is remarkable for its size and structure, being noticeably larger and wider than the zooecia, endozooecial and deeply embedded but very conspicuous because of the size (0.75 mm wide by 0.60 mm long) ; covered by the pigmented ectocyst, beneath which the ectooecial wall is extremely rough and perforated by numerous small pores. The ooecial aperture is a transverse slit 0.40 to 0.50 mm wide by about 0.13 mm long. The fertile zooecia are much modified, (gonozooecia), usually much shorter than normal zooecia and distally widening to the breadth of the ooecium; the peristome is a raised lip the full width of the ooecium, upon which it extends for a short distance. This species bears a close resemblance to T. unguiculata (Canu and Bassler) from the Gulf of Mexico, but the measurements are much smaller, the avicularia are shorter and located farther toward the distal end and the ooecial cover is perforated by numerous small pores. 444 ALLAN HANCOCK PACIFIC EXPEDITIONS voL. 14 Type, AHF no. 95. Type locality, Hancock Station 457-35, Secas Islands, Panama, 7°57'50’N, 82°01/15”W, 12 fms, several colonies on shells. Family Reteporidae Smitt, 1867 “Zooecia ovato-cylindrica secunda in stirpem reticulatam componun- ur.” This definition of the family by Smitt (1867:34) is very incom- plete, since not all fenestrate bryozoans can be included in this family and many which we now allocate here are not fenestrate. Levinsen (1909 :290) gives an extended definition from which we may sort out the following essential characters: zooecia heavily calcified, with few pores; spines present or wanting; a well-developed vestibular arch which is usually beaded ; dependent avicularia of varying size and form (usually a suboral one not in the midline) ; ovicell at first prominent but becom- ing immersed, often with a median fissure, above the orifice a labellum or prolongation (almost wanting in Rhynchozoon and Lepraliella in which there is a triangular or semicircular area above the orifice con- sisting of the endozooecial layer only). In the erect forms the zooecia are all on the frontal side and the dorsal side is covered by a layer of kenozooecia, which may or may not have pores and avicularia. Erect species are usually fenestrate, sometimes forming a close network, (rete- pores), but a few are merely branching or have only occasional fusions. Key To GENERA OF RETEPORIDAE 1. Zoarium erect, branching or fenestrate’. . . 5) .. 5) eee Hoarium encrusting i.) si &. 5 ao yy | of Rene: 2. Zoarium not fenestrate, or branches bale seca jcrte ovicell with a median fissure . . . . . . . Reteporellina Zoarium intricately fenestrate, forming a network; ovicell’ notifissuned) 2) Ws) ak 6) Se . 3) 3. Front of ovicell complete, with a noun belies: peristomes high obscuring aperture. . . . . . Phidolopora Front of ovicell incomplete above the aperture; peristomes high only on the sides . . . . . Schizoretepora 4. Ovicell with a small median fissure; aperture with a narrow, slit-like sinus: = 2). 1. //