494 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Genus UMBONULA Hincks, 1880. 



f'niliiiiiiila HIXCKS. British Marine Polyzna. p. 31 G. 

 There is neither lyrula nor cardelles. The apertura is suborbicular. The ovi- 

 cell is hyperstomial and opens largely above the apertura. The frontal is a pleuro- 

 cyst with costules surrounded by areolae. A prominent umbo immediately below 

 the month supporting an avicularium. '20-30 tentacles. 



FIG. 137. (ieiuis I'liiljriiiuJii Hincks. ]ssu. 



A D. L'tnbfiinila rcrnicusa Esper. 1791. A. Ordinary xnoecia. X -~>. B. Ovicelled zooecia. 

 < 3(j. (A, B after Hincks, 1880.) C. Avieularian mandible, X 85. (After Waters, 188.1.) 

 D. Young zooecium. The frontal shield is represented by a crescentic calcareous film, already 

 divided by radiating buttresses mi the upper surface intn distinct areolae () in the flour of 

 each of which is a pore (/>). The distal wings ( /. .\7/. <1 } of the shield are distinctly indicated. 

 The parietal muscles (p. HI.) are seen through the calcareous Him. ^CHI, parieto-vaginal muscles. 

 (After Harmer, 1902.) rex/, vcstibulum; u\>. ill., uperi'iilar glands; occl, occlusor muscles of tln j 

 operculum ; /. s., tentacular sheath; /). iiolypide bud. K. ( iperculum, X 40. F. Avieularian 

 mandible, X 200. ( E, F after Calvet, 1903.1 



Genotype. Umbonula (C'ellepo-nt) n n-in-ns// Esper. 1791. 



Range. Lutetian-Recent. 



The ovicell is analogous to that in Rhampkostomella Lorenz, 189G, but there is 

 no lyrula. It has not a deep peristomie as in Pon-Ha and Xniittin<i, into which the 

 ovioell opens. The place of this genus in this family is doubtful. Harmer in 1002 

 considered it as the type of a special family. 



UMBONULA (?) MISER, new species. 



Plate 94. fig. 19. 



l>< .w, 'i/if/nit. The xoarinm is unilamellar and creeps on algae. The zooecia 

 are elongated, distinct, quite irregular, little symmetrical, of an ugly aspect; the 

 frontal is convex, formed of a smooth pleurocyst surrounded by small triangular 

 areolae. The peristome is thick, irregular, hardly salient. The ovicell is small. 



