1171. HYDROIDA FROM ALASKA AND PrCETSOCND-NUTTING. 753 



EXPLANATION OF PLATES. 



Plate LXII. 

 Fig. 1. Sertiilaria tevera Sars. 



A. Portion of colony with gonangiuni. 



B. A pair of hydrothecii', enlarged. 



2. Campanularia kincaidi Nutting. 



A. Portion of colony showing characteristic hydrothecae. 



B. A single unusually large hydrotheca. 



C. Outline of aperture. 



3. Campanularia lineafa Nutting. 



A. Hydrotheca with pedicel. 



Ji. Side view of another hydrotheca. 



Platk LXin. 



IMg. 1. Halecium (/enirulatiim Nutting. 



A. Portion of colony sliowing hydranths and gonaugium. 



B. V, I). Single gouangia. 



2. Halecium corritgatnm Nutting. 



./. Portion of a colony growing on Sertiilarella triciiapidata. 

 li. A single hydrophore, enlarged. 



3. Hydrallmania dixtans Nutting. 



A. Side view of branch showing arrangement of hydrothecaj. 

 li. Anterior view of branch. 



C. Anterior view of a pair of hydrotheca', enlarged. 



D. Single hydrotheca, side view, showing apertnre. 



Plate LXIV. 



Fig. 1. Cross section of stem and gonosome of Lafoea dumoaa. 

 a. i. Axial tube of colony. 

 g., g.' Female gonangla. 



h. Hydrotheca containing a normal hydranth. 

 m. h., m. h.,' m. h." Greatly eiongated modiiied hydrothecie. 

 0, Ovum. 



p, t., p. t.,' p. t." Peripheral tubes of main stem. 



th., th.' Tubules or secondary tubes lorming a network around the periph- 

 eral tubes, and connecting the latter with tiie gonangla and modified 

 hydrothecie. 

 H. Male gonangium containing the spermary. 



2. Part of a section similar to the above, showing the sarcodal connection 



between the axial tube and the gonangium. 



ax. Axial tube. 



ha. Blastostyle of the female gonangium. 



c. (. Connecting tubule between the gonangium and the peripheral tube, 



g. The female gonangium. 



ov. Ovum. 



p. Peripheral tube traversed by sarcodal connection between the blasto- 

 style and axial tube. 



3. A single female gonangium, enlarged. 



hs. Blastostyle. 



or. The single developing ovum. 



4. A single male gonangium, enlarged. 



8. Spermary. 



Proc. N. M. vol. xxi 48 



