NO. 1171. HYDROIDA FROM ALASKA AND PUGET SO UXH—XUTTIXG. 747 



hydrotheca* than do those of H. distans. In H.falcaia each hydrotheca 

 attain.s a level above the middle of the next one above it, while in 

 H. distans it only attains the level of one-third the height of its suc- 

 cessor. 



Through the courtesy of Mr. Charles Fuchs, of San Francisco, I have 

 obtained a copy of the original description and figure of Hydrallmania 

 [Plnmularia) franciscana Trask.' 



It appears from both the original descriptions and the figure that H. 

 frunciscana differs from H.falcata and H. distans in having the hydro- 

 thecie distinctly flask-shaped and much narrowed at their distal ends, 

 being, according to the figure, more than twice as wide near the proxi- 

 mal end as near the aperture. H./ranciscana approaches H.falcata 

 and diflers from H. distans in having the hydrothec;e closely crowded 

 together on the front of the sten). 



LAFOEA DUMOSA Fleming. 



Specimens of this species collected in Puget Sound are provided with 

 well-develoj)ed gonosomes. The history of the discovery of the identity 

 of this structure and the genus Coppinia of Authors is an exceedingly 

 interesting one. The Lafocidie have been known and studied by sev- 

 eral generations of naturalists, who over and over again have scanned 

 abundant material for the long sought reproductive bodies, and all in 

 vain until Levinseu announced the final clearing of the mystery and 

 the discovery of the gonosome of one species at least, L./rnticosa.^ 



The story in brief is this: Dalyell in 1847-48 published a work 

 entitled '• Rare and Kemarkable Animals of Scotland," in which he 

 described under the name ^Sertularia aretica a remarkable form of 

 hydroid which ai)pejired as a parasitic growth forming an encrusting 

 mass on tlie other hydioids. Hincks' makes this species the tyi)e of 

 the family Coppiuida- and genus Coppinia, characterized as follows: 



Zoophyte consi.sting of a uuniber of long lubiilar liydiKtheose crowded closely 

 together and united liy au adherent cellular mass, which involves the lower portion 

 of them, the upper portion remaining free; ova developed iu tlie cavities of the cel- 

 lular mass, and escaping as planula'; polypites cjlindrical and very extensile. The 

 ova are produced iu the cavities or conipartmeuts which pervade the common con- 

 necting substance, and give a tessellated appearance to its upper surface.^ 



Coppinia is described as follows by Allman :* 



In this singular hydroid the hydrothecse and gonangia spring directly from a 

 creeping retiform hydrorhiza, wljile the gonangia, which are very numerous, become 

 closely adherent to one another Ijy their sides, so as to form with the proximal por- 

 tion of the hydrotheca' and with the hydrorhiza a continuous encrusting Ijasis 

 spreading over the surface to which the hydroid had attached itself. Each Gonau- 



' Proc. Cal. Acad. Nat. Sci., I, p. 113, pi. iv, fig. 3. 



- Meduser, Ctenophorer, og Hydroider fra Griinlauds Vestkyst., Copenhagen, 1893, 

 p.20. pi. VII, tigs. 2, 3, 



■' British Hydroid Zoophytes, ii. 218. 



* Monograph of the Gymuoblastic or Tubularian Hydroids, Kay Society, 1870, 1871, 

 1872, pp. 54, on. 



