﻿Plate 30 



1, Dendrostomum zoslericolum Chamberlin. Ensenada, Baja California; oral 



disk and base of six tentacles (1-VI), X 6, to show pattern of food grooves 

 and large upper lip, behind which is the nuchal organ (NO). \,a, one of the 

 small branches at base of tentacles; X 20. 



2, Dendrostomum hexadactylum Sato, Monterey Bay, Calif. Spines from intro- 



vert; X 25. 



3, Dendrostomum dyscritum, new species, paratype, Monterey Bay, Calif.; X 5. 



Contractile vessel above esophagus (0) showing the pattern of Polian tu- 

 bules for comparison with D. zoslericolum, in which the tubules are fewer and 

 do not branch, at least not at the base. 



4, Dendrostomum perimeces Fisher, X 200. Glands from posterior third of body 



to show the three sizes; the largest is seen somewhat from side. 



Plate 31 

 Dendrostomum zoslericolum Chamberlin 



1, Dissection of specimen from Ensenada, Baja California; X 1. The rec- 



tum, shown on right, in its natural position would be middorsal above 

 esophagus. Only G of the 1 1 Polian tubules have been completed. The 

 oblique bands of muscle in body wall are indicated as gray lines. 1, a, Is 

 posterior end of body omitted from 1. 



2, Side view of esophagus, X 5, to show contractile vessel and origin of Polian 



tubules. 



3, Rectum and associated structures of figure 1, X 2. 



4, A skin papilla from posterior third of body; X 200. 



5, Papillae from dorsal side of introvert near anus; X 65. 



A, position of anus; C, coecum; CV, dorsal contractile vessel; F^-F^, fixing 

 muscles; G, gonad; I, intestinal spiral, I A, ascending gut of spiral; ID, 

 descending gut; N, nephridium; A^*, nephrostome; 0, esophagus; O' , poste- 

 sophageal gut; PT, Polian tubules; S, spindle muscle; W, wing muscles. 



447 



