REPORT ON THE PENNATULIDA. 121 



EEPOET ON THE PENNATULIDA 



COLLECTED IN THE OBAN DREDGING EXCURSION 



OF THE BIRMINGHAM NATURAL HISTORY AND 



MICROSCOPICAL SOCIETY, JULY, 1881.* 



BY A. JIILNES MARSHALL, M.A., D.SC, PROFESSOR OF ZOOLOGY 

 IN OWENS COLLEGE, AND W. P. MARSHALL, M.I.C.E. 



I Continued from pag<- 56. ) 



PART II. — Pennatula Phosphorea. LinnaBus. 

 Of this species two living specimens were obtained, of 5^ and 4f 

 inches len^jth respectively. They were both found in the same locality 

 (Station I. of the General Report of the Dredging Excursion), two 



Description op the Figures in Plate III. 

 Figures I and 2, rei^resentiug the female specimen, are drawn directlj- from 

 the object. Figs. 3-7 are taken from the male specimen ; figs. :i, G, and 7 

 being drawn dii-ect with the camera from the original objects, while figs. 4 and 5 

 are constructed from separate camera drawings of the several parts shown. Fig. 

 8 is taken from one of the specimens from Naples. 



Alphaheticat List of References. 



a. Rachis. I o. Mesentery. 



b. Stalk. ; ov. Egg of Entomostracon embedded 



c. Stem. in mesenterial filament. 



d. Polype. ' ! p. Retractor muscle. 

 dl. Leaf. j q. Protractor muscle. 



e. Zooid. j r. Short mesenterial filament. 

 /. Tentacle. i .s. Long mesenterial filament. 

 fo. Foreign body, swallowed as food. t. Ovum. 



!7. Caly.x. ts. Spermatosphere. 



h. Cavity in caly.x process. u. Main canals of rachis. 



i. Spicule. ('. Smaller canals. 



I. Ccenenchym, or fleshy body- m. Ectoderm. ■ 

 substance. x. Mesoderm. 



m. Mouth. (/. Endodena. 



71. Stomach. 



Fig. 1. — Dorsal view of the female specimen, x g. 



Fig. 2. — Ventral view of the female specimen, showing zooids on ventral 

 surface of rachis : also ova at bases of leaves, x |. 



Fig. 3. — Transverse section through the rachis of the male specimen, with the 

 whole of the 13th left leaf, and the liase of the 13th right leaf. Shows mode of 

 formation of leaf by lateral fusion of polypes ; also arrangement of zooids on 

 rachis. On the right leaf the spicules are represented, but on the left they have 

 been omitted for the sake of clearness, x 3. 



Fig 4. — Longitudinal section of a single polype along the line A.\ in Fig. 3 ; the 

 plane of section being the jfj/t/ He n/s(//?i»iefry, perpendicular to the flat surface 

 of the leaf : shows whole structui'e of a polyije. x 17. 



Fig. .J. — Transverse section through si.x contiguous polypes taken along 

 the line BB in Fig. 3, cutting the several polypes at diffei-ent portions of their 

 lengths. '1 he uppermost section passes through the calyx and base of the 

 tentacles. The second section passes through the stomach, and shows the 

 mesenteries and the arrangement of the retractor muscles. The third section 

 passes through the mesenterial filaments below the stomach, and shows their 

 division into two small and si.x large ones : shows also food ijarticles in the act 

 of being digested by the filaments, and a ripe spermatosphere. The fourth, fifth, 

 and sixth sections are below the lower ends of the short niesenterial filaments; 

 they show the long filameuts, and the various stages of development of the male 

 reproductive organs, x 25. 



Fig. G.— Transverse section through one of the smaller spicules, x 400. 



Fig. 7. — Transverse section through a large spicule, x 400. 



Fig. 8. — Separate view of bare stem, x g. 



* Read before the Birmingham Natural Historv and Microscopical Society, 

 April 11th, 1882. 



