248 SERTULARIID^E. 



of larger growth than its ally, and wants its delicate, mem- 

 branaceous texture. The calycles do not shrivel in drying as 

 those of D. rosacea do. The stems are much firmer, and 

 of a decided horn-colour; they are commonly furnished 

 with long tendril-like extremities. These are occasionally 

 met with on D. rosacea as on other species, but they are 

 very characteristic of D. attenuata. The tendrils are com- 

 posed of a number of oblong pieces separated by joints 

 (Plate XLIX. fig. 1, d) . 



The branches are often long and slightly curved up- 

 wards, and exhibit the same comparative rigidity as the 

 main shoots. It is more difficult to describe the differences 

 in the calycles. Those of D. attenuata are longer and 

 more slender, and slightly suberect towards the aperture, 

 which is smaller and less "flaring" than in the allied 

 species ; they curve gracefully and gradually outward, and 

 do not bend abruptly. But the chief distinction is to be 

 found in the gonothecse, which seem almost top-heavy 

 with their profuse garniture of spines, some of them long, 

 slender, and acuminate, others shorter and stouter, and 

 wrinkled transversely. There are generally three on each 

 ridge, the uppermost being the largest and rising con- 

 siderably above the aperture. The capsules are sparingly 

 produced. 



After entering into these details, it must be added that 

 what may be called the egression of the species will enable 

 the student readily to recognize D. attenuata. Its erect and 

 somewhat stiffer habit, its decided horn-colour contrasting 

 with the pearly whiteness of rosacea, its slenderer branches, 

 its more erect and regularly pinnate form, and its long 

 tendrils will at once betray it to a quick eye. 



This form has been noticed by several previous authors, 

 but has been accounted a mere variety. Ellis has figured 

 it Avith the female capsule, referring it to rosacea (pi. iv. 



