66 coE 



terranean, though it is there comparatively rare and small. It is usu- 

 ally found between tides under stones in muddy localities. 



24. LINEUS TORQUATUS sp. nov. 

 pl. V, figs. 8, 9. 



Body rather thick and stout for the genus, somewhat flattened 

 throughout, but especially posteriorly and on the ventral surface. 

 Head short, pointed in front, somewhat narrowed behind, slightly flat- 

 tened. A slight annular constriction commonly marks off the head 

 region from that immediately following. Sometimes this constriction 

 is very conspicuous, and the head much narrower behind. Esophagal 

 region rounded above, flattened below. Intestinal region commonly 

 well flattened but without narrow margins. Posterior end slender. 



Cephalic furrows rather short. In alcohol or formalin they join 

 the terminal proboscis pore in front, but in life they are separated from it. 



Ocelli. — Absent, at least in mature individuals. Mouth a minute 

 pore or a large slit, according to state of contraction ; situated a little 

 behind posterior end of cephalic furrows. 



Color. — The color is usually dark, reddish-brown, chocolate, or pur- 

 ple above ; paler and commonly more reddish beneath. The dorsal 

 surface is often flecked with irregular minute, inconspicuous whitish 

 specks. A narrow transverse white band passes across the dorsal sur- 

 face at the posterior ends of the cephalic furrows. This characteristic 

 marking reaches only to the lateral edges, and is not seen from the ven- 

 tral surface. The cephalic furrows are sometimes, but not always, 

 bordered above and below by a narrow band of white. Furthermore 

 a minute white spot occupies the region of the proboscis pore. The 

 white borders of the cephalic furrows commonly connect this white 

 spot with the white transverse dorsal band on the posterior portion of 

 the head. On the extreme tip of the snout — in the white area around 

 the proboscis pore — a pair of small pigment spots is sometimes pres- 

 ent, one on each side of the proboscis pore. 



Size. — Length usually 200 to 400 mm. in extension, width about 

 5 mm. 



Proboscis. — The proboscis is moderately slender and of medium 

 size. It is without color. The inner longitudinal muscular layer is 

 almost entirely wanting ; the crosses between the circular layers are 

 distinct, and the nervous plexus is exceptionally well developed. A 

 single pair of large nerves enters the proboscis at its point of attach- 

 ment at its anterior end. They originate from the ventral commissure 

 of the brain near the ventral ganglia, enter the proboscis from the ven- 



