SABELLIDES AND SERPULIDES 235 



bearing on its upper surface a central crown of 10 or 11 long, tapered, 

 upward-curving, simple, horn-colored spines characteristic of EupO' 

 matus uncinatus Philippi (1844) figured by Ehlers 18S7; secondary 

 operculiuTi small, club-shaped, on a very short stem. One specimen 

 has only a central horn-colored ring, the crown of spines having been 

 lost, and the margin has apparently been injured on one side, where 

 the serrations have grown together, forming an angulation. 



Thoracic segments 7 ; abdominal segments over 70 in the largest 

 example, which has lost a posterior portion. 



A very wide membrane borders the thorax, forming a very deep 

 collar with lateral incisions or clefts but with no median one, the ven- 

 tral edge being entire; there is, however, a conspicuous oval opening 

 considerably within the margin. 



Setae similar to those in Serpula. 



Length of thorax 3.5 mm. ; breadth 3 mm. ; length of longest bran- 

 chia 5.5 mm. ; diameter of operculum 2.5 mm. 



Pacific Grove, California, August, 1901, three specimens. 



The tubes are solitary, variously twisted, and attached for the greater 

 part of, if not their entire length. The surface, roughened by growth 

 lines, is often rust colored, covered with bryozoa and other animals. 



Hydroides frotulicola Benedict (1886), specimens of which are in 

 the Yale Museum, is a typical Eupomatus^ as is undoubtedly H. 

 spongicola Benedict, judging from the figures. Serpula dianthus 

 Verrill (1874) is also an Eupomatus . In Hydroides (type, H. nor- 

 vegica Gunnerus) the spines forming the crown on the operculum 

 have conspicuous lateral processes or secondary spines. 



EUPOMATUS HUMILIS sp. nov. 

 pi. xxxix, figs. 39, 40 ; pi. xLiv, fig. 22. 



Type locality. — Guaymas, Mexico. 



A small (probably immature), thin, very slender, round tube, form- 

 ing one long irregular loop, is attached its entire length to the side of 

 a small coral. 



The five branchiae are long, stout, with few pinnae, the very small 

 characteristic operculum on its very slender peduncle reaching above 

 them. The operculum is colorless, with coarsely serrate margin, 

 formed by about 10 long, broad points, crown of 8 long, simple, char- 

 acteristic spines, each with a basal spinule on its inner surface. 



Number of segments unknown, only the anterior portion having 

 been found. Collar setae few in number, the superior ones with 4 



