coe: nemerteans of west and northwest coasts. 229 



are larger, more closely placed in their bundles and stain more 

 deeply. In esophageal region these muscles become arranged just 

 internal to the longitudinal muscles of body walls and form a por- 

 tion of this layer. In no other sj^ecies has any such condition 

 been described, though an approach to it is met with in A. nebulosus 

 (Coe, : 01, p. 49), where the submuscular glands develop to such an 

 extent as to form a distinct layer which divides the longitudinal 

 muscular layer into an outer and an inner portion. In A. gelatinosiis 

 .also, as described on ]». 'iOO, a few longitudinal muscles lie above the 

 proboscis sheath in the brain region, but these connect almost 

 directly with the proboscis sheath and body muscles, and do not 

 extend for any considerable distance either anteriorly or posteriorly. 



Alimentary canal. — The pylorus is remarkably short, being only 

 about twice as long as the distance from tip of snout to brain. It 

 then enters the dorsal wall of the intestinal canal, which in this case 

 corresponds in position and histological structure to the intestinal 

 caecum of other forms, although it does not end blindly and in this 

 case must be called the anterior chamber of the intestine. An 

 extremely short caecum proper is, however, j)resent and extends 

 forward with a few pairs of lateral lobes for a very short distance 

 anterior to the posterior opening of the pylorus. This condition has 

 evidently arisen from the disappearing of the long, slender pylorus 

 of the ty])ical Hoplonemertean, so that the pylorus opens very near 

 the anterior end of the long caecxxm instead. of far back as in most 

 other members of the order. Both this anterior intestinal chamber 

 and the caecum proper have the same anatomical and histological 

 peculiarities. Hoth send oft" j)aired lateral diverticula, which are 

 closely placed together, of rather small size, extending laterally 

 somewhat above the latei'al nerves, and provided with the deep 

 green pigment mentioned above. Toward the posterior end of the 

 anterior chamber the diverticula become longer and the canal grad- 

 ually takes on the character of the intestine ])ro])er near the most 

 anterior sexual glands. 



lilood and nephridial sy.^tenis. — The blood vessels of head and 

 esophageal region are all of small size, and extend on all sides above 

 proboscis sheath and beneath esophagus, as well as laterally. Back 

 toward the intestinal region they form the usual [)air of lateral 

 vessels. 



Efferent nephridial ducts were not found, nor Avere there any 



