Intertidal Bryozoa (Cheilostomata) of Ketchikan, Alaska Author Dick, Matthew H. Author Grischenko, Andrei V. Author Mawatari, Shunsuke F. text Journal of Natural History 2005 2005-12-23 39 43 3687 3784 http://dx.doi.org/10.1080/00222930500415195 journal article 10.1080/00222930500415195 1464-5262 5220912 Microporella setiformis O’Donoghue and O’Donoghue, 1923 ( Figure 18C, D ) Microporella setiformis O’Donoghue and O’Donoghue 1923 , p 32 , Plate 3, Figure 21 ; 1926, p 65, Plate 5, Figure 44. Microporella setiformis : Osburn 1952 , p 385 , Plate 44, Figure 8 ; Soule et al. 1995 , p 150 , Plate 53. Description Colony. Unilaminar, encrusting; white, covered with shiny ectocyst. Zooids. Irregularly hexagonal, distinct, separated by a deep groove; variable in size and shape, markedly elongate or nearly as wide as long; 0.55–0.80 mm long (average 50.666 mm , n 511, 1) by 0.40–0.58 mm wide (average 50.492 mm , n 511, 1). Frontal wall. Convex, rising sharply around margin, flatter on top, even, without umbo, finely granulated; with 10–14 areolar pores along each lateral margin and smaller, slightly infundibular pores over entire surface. Orifice. As wide as or slightly wider than long, 0.10–0.13 mm long (average 50.122 mm , n 511, 1) by 0.13–0.15 mm wide (average 50.138 mm , n 511, 1); sides recurve slightly toward proximal margin, which is shallowly concave between small, shelf-like condyles; peristome a low, smooth, rim around curvature of orifice, with a straight hinge shelf along proximal margin. Ascopore. More-or-less circular, often with a small denticle projecting from the distal margin; surrounded by a flat, smooth collar abutting proximal rim of orifice. Spines. No spines or spine scars evident in our specimens. Avicularia. Small, oval; near zooidal margin lateral to ascopore on one or both sides, pointing distolaterally, with a setose mandible roughly three times as long as rostrum. Ovicell. Not observed. Ancestrula . Not observed. Remarks Microporella setiformis was rare at Ketchikan; we collected two colonies at Higgins Point. Although we observed no spines or spine scars, both Osburn (1952) and O’Donoghue and O’Donoghue (1926) reported this species to have five evanescent oral spines on marginal zooids. Distribution Microporella setiformis is a boreal species endemic to the north-eastern Pacific. Osburn (1952) summarized records from numerous localities in British Columbia , Puget Sound, and as far southward as the Channel Islands in Southern California . Ketchikan is the northernmost extent of the known range .