Fitter. California Coast Ascidians. 41 



Psammaplidium spauldingi, n. sp. 



PI. 3, fig. 39. 



General Characters of tJie Colony. Expanded, loosely adher- 

 ent by whole under surface, top smooth but undulating-, hard 

 from great quantity of sand, which is uniformly disseminated 

 through the whole test. Edge of the colony rolled up a little. 

 The small zooids numerous, evenly distributed, no systems (?), 

 each branchial orifice marked on surface of colony by a small 

 papilla-. Color uniform grey, due to the imbedded sand. 



The single colony taken, 6 cm. by 5 cm. in its greatest dimen- 

 sions and 1.8 cm. thick in thickest part, though considerably thin- 

 ner in most places. 



Zooids. Abundant, long, slender and nearly straight, the 

 thorax but little thicker than the abdomen and long post-abdomen. 

 Thorax about 3 mm. long; abdomen, before contraction, probably 

 about 2 mm. ; post-abdomen variable, but several times as long as 

 thorax and abdomen combined. Mantle containing a few slender 

 longitudinal muscle bands which extend far down into the post- 

 abdomen. 



Thorax. Branchial orifice on prominent siphon, six-lobed, 

 atrial situated well back a distance from the end of the bran- 

 chial siphon about equal to the thickness of the thorax. Atrial 

 orifice beset with a moderately long languet, this usually undi- 

 vided, but occasionally bifid at tip. The long cylindrical sac with 

 about eighteen series of short stigmata, muscle bands in inter- 

 stigmatic series well developed. Endostyle large and tortuous. 

 Branchial tentacles about ten, unequal in length, some of them 

 quite long. 



Digestive Apparatus. Loop narrow, esophagus about equal- 

 ing the stomach in length, and also about equal both in thickness 

 and length to the pyloric portion of the intestine. Stomach with 

 three or four large longitudinal folds or lobes. A distinctly set- 

 off enlarged section of the intestine following- the pyloric portion. 

 Ascending rectal limb of the intestine straight, uniform in 

 diameter and parallel with the descending limb. 



Gonads. Far behind the intestinal loop in the post-abdomen, 



