94 



AMERICAN HYDEOIDS. 



Distrihution. — British Coasts (Wright, Hincks, and others) ; Puget Sound (Calkms) ; 

 Atlantic Coast, United States (Fraser, MSS.). Mayer' considers this species as identical with 

 PMalidium Iwmisphsericum (Gronovius) and states that the hydroid "is probably a Campanu- 

 lina" and refers to Hincks^ where he (Mayer) is doubtless misled by a figure of LoveneUa clausa 

 on the opposite page from the description of TJiaumantias inconspicua. This figure, however, 

 has no reference to TTuiumantias at all and the hydroid form of T. inconspicua is, as above shown, 

 indistinguishable from Campanularia. It is true that Brown and Mayer both describe the 

 medusae of this form as having Uthocysts, but Hincks distinctly says that they are absent 

 and bases his genus on that fact. It does not seem hkely that so careful an observer as Hincks 

 would fail to see these structures. It seems more probable that Hincks and van Beneden 

 were describing different medusee, and that the latter writer was describing a Campanulina 

 while Hincks had a form whose hydroid phase was indistinguishable from Campanularia. 



Family BONNEVIELLIDiE Broch. 



BonTieviellidx Broch, Hydroiduntersuchungen II, Zur Kenntnisa der Gattungen Bonneviella und Lictorella, 1909, 

 p. 197. 



The origmal definition of this family is entirely satisfactory and will be adopted here. 

 The following is a translation: 



Bonneviellidje; Calypteroblastic hydroids with a well-marked veloid, so that a preoral cavity is formed. 



The present Avi'iter has made an examination of longitudinal sections of his ' ' Campanu- 

 laria regia," a close relative of Bonneviella grandis (Alhnan), type of the family, and has been 

 able to confirm the obser- 

 vations of Broch. A mem- 

 brane, which the writer had 

 previously regarded as the 

 proboscis, stretches from the 

 tentacle bases above the real 

 oral surface. The center of 

 this membrane is perforated 

 by a round aperture directly 

 over the true oral opening. 

 The "preoral cavity" (fig. 

 69, p o) thus formed is lined 

 throughout with ectoderm, 

 thus showing a remarkable 

 approach to the gullet or 

 esophagus of zoantharians 

 in its structure. The "veloid" (fig. 69, v) or membrane itself is composed of two layers of 

 ectoderm separated by a stutzlamella. 



Aside from this remarkable and important character this form would have to be removed 

 from the family Campanularidse on account of not having the trumpet-shaped proboscis char- 

 acteristic of that family. Indeed it has no proboscis at all, the real oral surface being actually 

 a depression whose lowest point is occupied by the mouth. 



STKUCTUEAL DETAILS OF BONNEVIELLA GRANDIS. 



(After Broch.) 



Fig. 69. — Oral region and upper part of gastric cavity. 6, Tentacle base; p. o., pre-oral cavity; 



f, vellum; * * *^ opening from mouth to gastric cavity. 

 Fig. 70. — Basal region, showing connection of hydranth with the hydrotheca. a, Diaphragm. 



KEY TO AMERICAN SPECIES OP BONNEVIELLA. 



Hydrothecse tubular, with everted margins . 



Gonangia lageniform, longitudinally ribbed grandis. 



Gonangia cylindrical, transversely corrugated. 



Hydrothecse large, up to 3.5 mm. long regia. 



Hydrothecse immense, up to 10.7 mm superba. 



Hydrothecae campanula te, margin not everted ingens. 



1 MeduBje of the World, vol. 2, 1910, p. 266-267. = British Hydroid Zoophytes, 1868, p, 179. 



