1907] Fitter. — California Coast Ascidians. 5 



ally .smaller than those between the folds. Transverse vessels lim- 

 ited to the folds, and to the intervals between the infundibula, 

 pi. 1, figs. 5 and 6. 



Intestinal Tract. — Wide, simple open loop sitnated across the 

 posterior dorsal side of the animal, somewhat to the left. Stom- 

 ach not large, sharply set off from the esophagus but not from the 

 intestine, the Avail irregularly folded. Anus bordered by five or 

 six petaloid lobes. Benal organs in the form of two or three dis- 

 tinct patches on the inner surface of the mantel in the vicinity of 

 the gonads, the largest patch being lateral to the right gonad. 

 Gonads one on each side of the body, the left in the intestinal loop, 

 each long and sausage-shaped. 



The dull white, clean-surfaced, egg-shaped habitus of this fine 

 species gives an assemblage of the animals a striking appearance. 

 The coreaceous consistency of the test causes the specimens to 

 keep their form to an unusual degree, in spite of the action of pre- 

 serving fluids. Nearly all of the hundred and fifty individuals 

 examined were attached to a net-like hexactinellid sponge, and 

 considerable expanses of the sponge are still adhering to the spec- 

 imens. The minute, close-set, rigid spicule-bearing processes of 

 the test give the surface considerably the nature of the chagrin of 

 some sharks. Examination of the processes with a hand lens dis- 

 covers them to be arranged about the orifices in cjuite regular 

 fashion (pi. 1, fig. 2). In perspective the processes are regularly 

 goblet-shaped, with the mouth of the goblet taking the form of the 

 Greek acanthus. Each secondary process, corresponding to the 

 petal of the acanthus flower, contains a rod-like calcareous spicule, 

 the distal end of which is i^ointed, and corresponds to the tip of 

 the process. The spicules do not occur in interior parts of the 

 animal, excepting on the inner surface of the siphons and over a 

 small, well-defined area on the inside of the branchial and atrial 

 chambers, immediately around the orifices. These areas in all 

 probability mark the inturned portion of the ectoderm. After the 

 spicules are destroyed with acid a considerable cluster of cells is 

 observable in the tubercles containing them. These probably 

 produce the spicules. The question of the lobulation of the 

 orifices in this species is unusually difficult. PL 1, fig. 2, shows 

 the branchial orifice as seen in a surface view in a specimen with 



