DIPHASIA ATTENUATA. 247 



rally distributed. It ranges from between tide- marks to 

 deep water. 



[Very abundant in 50 fath., gravelly bottom, in the 

 Straits of Belle Isle (A. S. Packard, jun.): Massachusetts 

 Bay (Agassiz).] 



2. D. ATTENUATA, HillclvS. 



SERTULARIA ROSACEA, Ellis, Cor. 9, pi. iv. fig. C?; Juhnst. B. Z. 470 (speci- 

 men from Orkney, Lieut. Thomas). 

 PINASTER, var., Johnston, B. Z. 72, figs, c, d. 



ATTEXUATA, HincJcs, On new British Hydroida, Annals N. H. 



for October 18C6, (3rclser.)xviii. 298. 



Plate XLIX. fig. 1. 



STEMS straight, somewhat rigid, pinnately branched, often 

 running out above into long tendril-like filaments, which 

 are thickened and bifid at the extremity; branches simple, 

 or bearing one or two ramules, alternate, inclined upwards, 

 sometimes furnished with tendrils ; HYDROTHEC.E tubu- 

 lar, slender and gracefully curved, about half their length 

 free and divergent, but not abruptly bent, with a plain, 

 suberect aperture ; GONOTHEC.E (female) elongate-pyri- 

 form, tapering off below, and gradually expanding up- 

 wards, bristling with strong spines above, which are 

 arranged on six longitudinal ridges, and extend down the 

 upper third of the capsule ; (male) ovate, with six longi- 

 tudinal ridges, terminating above in angular points, the 

 aperture subconical, rising in the midst of them. 



THIS pretty species has been confounded with D. rosacea, 

 to which it bears some general resemblance. The habit 

 and texture of the two, however, are strikingly distinct ; 

 so are the reproductive capsules, and there are also dif- 

 ferences, though minute, in the form and arrangement of 

 the calycles. D. attenuata is more robust and rigid and 



