LEPTOMEDUS.E EUCOPELLA. 



233 



Eucopella bilabiata. 



Campanularia bilabiata, Coughtrey, 1875, Trans. New Zealand Institute, vol. 7, p. 293, plate 20, fig. 45 (hydroid). 



Campanularia compressa, Clarke, 1876, Proc. Acad. Nat. Sci. Philadelphia, p. 214 (hydroid only). 



Eucopella campanularia, von Lendenfeld, 1883, Zool. Anzeiger, Jahrg. 6, p. 186; 1883, Zeit. fUr wissen. Zool., Bd. 38, p. 497, 



taf . 27-32, 37 fign. (hydroid and medusa).— Bale, 1888, Proc. Linnean Soc. New South Wales, ser. z, vol. 3, p. 751 , plate 1 3 



figs. 9-15. 



(>)Clyiia compressa, Nutting, 1901, Proc. Washington Acad. Sci., vol. 3, p. 170, plate 17, figs. 3,4 (hydroid from Alaska).— 

 Torrey, 1902, University of California Publications, Zoo!., vol. 1, p. 58, plate 6, fig. 49 (hydroid from California). 



Medusa.—- Bell pyriform, 1.5 mm. high; walls thin, thinnest at rounded apex. 30 to 40 

 meridional ridges extend up exumbrella from velar margin to near apex; these are especially 

 prominent when the medusa contracts. Each ridge is said to be composed of a strand of 

 meridional "nerve-fibers," which branch off from the outer nerve-ring at the bell-margin. There 

 are 8 adradial lithocysts, each with a single concretion. No trace of tentacles. Velum is well- 

 developed. Ring-canal narrow. The 4 radial-canals extend from the ring-canal to near bell- 

 apex, before reaching which they are closed and obliterated. They give rise to numerous 

 side branches between the gonads. There is no manubrium. The ripe ova are found in 

 two rows in the entoderm on both sides of the radial-canals between the side branches of the 

 canals. The spermaries are ectodermal and occur in 4 large, longitudinal swellings over the 4 

 radial-canals. The bell-cavity is almost filled with the genital organs. The medusa is color- 

 less except the entoderm of the 4 radial-canals, which is brown. It lives but a few hours 

 and soon discharges its genital products. 



Fig. 120.— Eucopella bilabiata, after von ~~ C ^CC£3U_I_\^^^*' '-. W (S I I 120. 



Lendenfeld, in Zeit. fiir wissen. Zool. 



Showing ripe medusa and forms of 



hydrothecte. 

 Fig. 121. — Agastra mira, after Browne, in 



Proc. Zool. Soc. London. 



Hydroid is a Campanularian. The stems are simple, unbranched, 4 to 6 mm. high, and 

 arise singly from a hydrorhiza which forms an open network over Laminaria. The stem's are 

 smooth, with one or two ring-like constrictions at base of hydrotheca:. Hydrotheca bell- 

 shaped and constricted at its upper, open end. The lip is simple and entire, without serrations. 

 The polypite is elongate, spindle-shaped, with a flaring mouth and a single zone of 32 filiform 

 tentacles. The base of the polypite at bottom of hydrotheca is wide. 



The gonophores are placed upon short unringed pedicels and attain a height of 2 to 3 mm. 

 They are laterally flattened and elliptical in cross-section. The gonophore develops two 

 medusa-buds, one small (lower) proximal and one large (upper) distal medusa. When the 

 upper one is discharged the lower one develops so as to fill the lower half of the gonophore. 

 The female germ-cells are entodermal and develop in the ccenosarc of the hydrorhiza and fin- 

 ally migrate into the entodermal linings of the side branches of the radial-canals of the medusa. 

 The sperm is ectodermal and develops over the radial-canals of the medusa-buds. The ento- 



