48 COE 



Cerebral sense organs. — Smaller than in most species of the genus. 

 They are situated slightly in front of the brain, but are well separated 

 from it because they lie near the ventro-lateral border of the head. 

 The canals placing them in communication with the exterior are, con- 

 sequently, extremely short. Each canal opens into the shallow, 

 oblique furrow on the side of the head. The posterior ends of the 

 sense organs lie beneath the anterior borders of the ganglia, but much 

 nearer the ventral surface. A pair of large nerves given off from the 

 dorsal ganglia opposite their commissure connect with the sense organs. 

 The lateral nerve cords unite above the posterior end of the intestine 

 as usual. 



The body cavity in the esophagal region is filled with an unusually 

 large amount of gelatinous tissue, which occupies the considerable 

 space between the muscular layers and the esophagus and proboscis 

 sheath (p1. x, fig. 4). In this gelatinous tissue the lateral nerves are 

 situated, and through it a complex system of blood vessels and nephri- 

 dial canals ramifies. 



The intestinal caecum is very broad and has but short lateral diver- 

 ticula. It lies wholly beneath the esophagus, and the branches do 

 not extend above the lateral nerves. The cascum ends anteriorly far 

 behind the brain region. The esophagus becomes very small before 

 it empties into the dorsal wall of the broad intestine. 



The attachment of the proboscis to the tissues of the head, the posi- 

 tion of the rhynchodaeum and its openings into the esophagus and pro- 

 boscidial cavity, the position of the dorsal and ventral brain commis- 

 sures, the cephalic glands and other organs are shown in p1. x, fig. 4. 



Tlie sexual products are mature in June. The whole body becomes 

 distended with the pouches of sexual elements, and the cavity of the 

 alimentary canal is much reduced in consequence. The ova are large 

 and deep olive-green. 



The length of the specimens obtained, both males and females, was 

 about 75 to 100 mm. in extension. 



Habitat. — This species was met with only at Farragut Bay, where 

 it occurred under stones in muddy locations at about half tide. 



16. AMPHIPORUS NEBULOSUS sp. nov. 



p1. IV, fig. I ; rl. VIII, fig. 6; pi. xi, fig. i. 



13ody short, rather broad, and much flattened ; narrower anteriorly 



than in the intestinal region, and tapering gradually posteriorly. 



Mouth sub-terminal ; head pointed or expanded in front, according to 



