114 BULLETIN: MUSEUM OF COMPAKATIVE ZOOLOGY. 



epithelial, and do not aifect the even contour of the underlying 

 basement membrane (PI. 15, fig. 91). 



The lateral sense organs are hkewise very highly developed. 

 They are indicated externally by a pair of rounded pits lying in, or 

 just anterior to, the fifth white ring and immediately below the 

 doi'sal of the two white longitudinal lines on each side. The sense 

 organs are sharply distinct from the surrounding epithelium. They 

 lie just dorsal to the lateral nerves, and immediately external to the 

 basement membrane. The slender e])ithelial cells of which they 

 are comjiosed are scarcely one third as high as the surrounding 

 epithelium, and although there are very numerous gland cells in 

 their basal portions, yet these glands are minute in size, and not 

 conspicuous. The surrounding epithelium overlaps the sense organs 

 considerably, but is separated by narrow infoldings or constrictions 

 reaching inward nearly to the basement membrane (PI. 15, fig. 91). 

 Numerous nerve fibers pass directly to the sense organs from the 

 lateral nerves, as Burger ('95) has so fully described for other species 

 of the genus. Muscular fibers extend to all parts of the sense 

 organ, so that it is capable of considerable independent motion and 

 may be depressed or elevated at the control of the animal. 



Habitat. — The species is widely distributed, having been collected 

 at Sitka, Alaska, and Puget Sound, both by Griffin ('98) and Coe 

 (:01). It is common on piles of wharves at Monterey and at San 

 Pedro, Cal., living in twisted, parchment-like tubes. Some individ- 

 uals collected were no more than 75 mm. in length, wliile otliers 

 were more than a meter when fully extended. The average size of 

 numerous specimens collected in California in 1901 was about 20 cm. 



3. Carinella capistrata Coe. 

 Proc. Washington Acad. Sci., 3, i*. 10, PI. 1, fig. 1, 1901. 



Carinella cajnst7X(ta Coe. Harriman Alaska Ex])edition, 11, pj). 

 16, 118, PI. 1, fig. 1, 1904. 



In shape, size, color and markings of body resembhng ( '. sivperba 

 somewhat closely, but may readily be distinguished by the absence 

 of a median, ventral white line. Markings on head and arrangement 

 of anterior white rings distinguish it from C annulata and C nothus. 

 Arrangement of markings is likewise different from that in O. sexline- 



