PLATE VII. 



[All of the sections were drawn in outline by the aid of a camera lucida. All 



the figures except 9 are oi Harrhnania inaculosa.'\ 

 Figs, i and 2. Lateral and dorsal views, respectively ; original drawing, 



from living specimen ; 7^ natural size. 

 Fig. 3. Schematic representation of dissection ; collar and small portion of 

 anterior pharyngeal region of same species. The anterior section 

 is far forward in the collar, slightly behind the anterior neuropore. 



4. Mid-collar region. 



5. Dorsal portion of esophageal wall, body of nuchal skeleton, and isth- 



mus of nuchal notochord. 



6. Transitional region from nuchal to esophageal notochord. 



7. Dorsal portion of esophagus with esophageal notochord in sections 



farther back than the last figure. 



8. Epibranchial band, ep. b., with a pair of gill bars, g. b. 



9. Dorsal portion of esophagus of Dolichoglossus intermedins, showing 



remnant of esophageal notochord at es. no. c' . 

 ID. Outline drawing of esophagus and esophageal notochord a short dis- 

 tance behind body of nuchal skeleton. 



Abbreviations Used in the Figures. 



A Anterior. 



b. n. sk Body of nuchal skeleton. 



br. ep Epithelium of branchial bar. 



br. o Branchial orifices. 



d. n. c. Dorsal nerve cord. 



d. b. V Dorsal blood vessel. 



d. s Dorsal septum. 



ec Ectoderm. 



ep. b Epibranchial band. 



es. no-c. Esophageal notochord. 



es Esophagus . 



g. h Gill bar. 



i. I. c. VI Inner longitudinal collar muscle. 



/. p. and r. p Left and right notochordal pockets. 



/. w. and r. ze/.-.I/cft and right wings of nuchal notochord. 



m. n. no-c Median portion of nuchal notochord. 



ni. r Median ridge of esophageal notochord. 



P. Posterior. 



ph. c. Pharyngeal cavity. 



p. hcs. s Perihaimal spaces. 



sk. c. Skeletal crura. 



V. ep Ventral epithelium of nuchal notochord. 



(>32) 



