76 coE 



The worms were found near low water mark living in soft black 

 mud beneath a considerable growth of 'eel grass.' The mud contained 

 a great quantity of decomposed vegetable matter, and was saturated 

 with sulphuretted hydrogen. The worms are excellent swimmers, and 

 are very rapid in their movements in their underground burrows. 



The specimens obtained measured up to 500 mm. or more in length, 

 and about 15 mm. in width. 



The color above was slaty-brown, dark gray, or greenish-gray, with 

 white or colorless margins. 



The species has been previously recorded from the Mediterranean, 

 the coasts of Great Britain, Madeira, the northeastern coast of Amer- 

 ica, Greenland, and from other localities. 



29. CEREBRATULUS OCCIDENTALIS sp. nov. 



p1. VI, fig. 3. 



Body 300 mm. or more in length in moderate extension ; rather slen- 

 der, rounded in front, flattened behind, and with very thin margins in 

 the intestinal region, as in other species of the genus. Head change- 

 able in shape, either rounded or acutely pointed, according to state of 

 contraction. Cephalic furrows rather short. 



Color. — Individuals vary considerably in the general color of body, 

 but are most commonly chestnut brown or dull reddish anteriorly, and 

 light chocolate brown in the intestinal region. The ventral surface is 

 brownish flesh-colored, with a median, ochre ventral stripe. Some- 

 times the ventral surface is nearly chocolate throughout its entire length. 

 A darker median dorsal stripe is indicated. 



Proboscis. — Remarkably small and slender, being many times 

 smaller than in most related species of equal size. It is colorless, and 

 is usually everted when the animal is killed. 



In internal anatomy but few points need special mention. The 

 cephalic glands are unusually well developed, and continue backward 

 as the cutis glands. The brain is remarkably voluminous, the dorsal 

 ganglion bilobed, the lower lobe continuing into the cerebral sense 

 organ. 



The mouth is very large, and is provided with an unusual abundance 

 of buccal glands. There are many diagonal fibers between the pro- 

 boscis sheath and the body musculature. 



Nephridia. — The nephridia are of moderate length, aiid occupy 

 the middle third of the esophagal region. The main tubules lie in the 

 angles between the esophagus and the proboscis sheath. They are 

 profusely branched towards their anterior ends, each branch lying in 



