142 COE 



cells, which present a sharp contrast to the neighboring cells of the 

 integument because of their comparative freedom from secretion. The 

 general appearance of the sense organ is similar to that figured for C. 

 frenata (pi. xxii, fig. 2). 



Reproductive Organs. — Sexual products mature in September. 

 Sexual pouches are usually situated dorsally to the lateral blood vessel, 

 and open on the dorsal aspect of the body. 



Habitat. — Monterey Bay, Calif. Shallow water; not common. 

 Dredged from soft bottom in fourteen fathoms off McAbee's Beach, 

 Monterey Bay, Calif., by C. B. Wilson, 1S99. 



Nemertopsis Biirger 

 Fauna and Flora des Golfes von Neapel, Monogr. 22, p. 548, 1895. 



Representatives of this genus are characterized by extremely long 

 thread-like bodies of firm consistency. They resemble Emplectonema 

 In form, habits and general internal anatomy, but differ in having only 

 four ocelli, which are symmetrically placed on the head, in armature 

 of proboscis, and in other anatomical details. 



The worms are quite as slender as those of the genus Cephalothrix., 

 but they do not coil the body in a spiral. 



Proboscis sheath very short, proboscis armed with well-developed 

 central stylet and basis, and with two pouches of accessory stylets; 

 cerebral sense organs small, situated well in front of brain. Cephalic 

 glands usually well developed. 



But two species of this genus have thus far been described, both 

 of which have been found in the Mediterranean. A third form, de- 

 scribed below, occurs on the Pacific coast of North America. 



4. NEMERTOPSIS GRACILIS sp. nov. 

 pi. XV, fig. I ; pi. XX, figs. 10, II. 



This very slender species bears a close external resemblance in form 

 and color to N. peronea (Quatr.) Burger, but differs in several fea- 

 tures of internal organization, especially in the structure of the pro- 

 boscis armature and the extent of the intestinal caecum. 



Like N. peronea the body is extremely long and slender, probably 

 more so than any other Nemertean found on the coast except species 

 of Ccphalothrix. The body is commonly 10 to 15 cm. or more in 

 length, and usually less than i mm. in breadth. The head is slightly 

 broader than the body, which is somewhat flattened dorso-ventrally, 

 but of nearly equal width throughout its length. Mouth and proboscis 

 have a common opening. 



