DAVENPORT, — Cerata in Molis. 
PLATE L 
ABBREVIATIONS. 
an. Anus. ya. Stomach. 
can. comn. Communicating canal. ga.” Prolongation of stomach back- 
cer.1,2,etc. Cerata of the same trans- wards. 
verse series. ga dv. Gastric diverticulum at base of 
cn’ph. Cnidophore. transverse rows of cerata. 
ca. Hepatic cecum. ms'chy/ Mesenchyme of developing 
cæ! Forming hepatic coecum. ceras. 
epl. Capillary vessel. CA (Esophagus. 
ec'drm. Ectoderm. pd. Foot 
ec'drm.^ Ectoderm of young ceras. rt. Rectum. 
en’drm.’ Entoderm of young ceras. 
Figs. 1,2. Two figures of young individuals of /Rolis sp., showing arrangement 
of cerata in transverse rows, which are numbered with Roman 
numerals. X 5. 
3. Transverse section of a young JEolis showing the stomach, the gastric 
diverticulum, and hepatic coca of a transverse row of cerata. X 45. 
4. Outline of alimentary tract of ZBolis, copied from Alder and Hancock, show- 
ing gastric diverticula and points of connection of hepatic coca. 
5-8. Four vertical sections through different stages in the development of the 
cerata. 
First stage in formation of ceras. Mesenchyme thickened at ms'chy. 
Right side. X 405. 
6. Second stage in formation ot ceras. Mesenchyme thiekened still further. 
Ectoderm beginning to evaginate in the axis. Left side. X 405. 
7. Third stage in formation of ceras. Gastric diverticulum beginning to out- 
fold to form hepatic cocum of new ceras. Left side. X 228. 
Fourth stage in formation of ceras. Right side. 28, 
