3 



SABELLARIA. 

 GENERIC CHARACTER: Tubes numerous, composed 

 of sand and fragments of shells, united into a common 

 mass by means of a glutinous substance excreted by the 

 animal; the orifices separate to each individual, cup- 

 shaped. 



* S. ALVEOLATA. Sabella A. Turt. Lin. Pen. Brit. Zo., 

 vol. 4, pi. 92, fig. 1G*2, the figure from an injured specimen. 

 Stew. Elem. Nat. Hist., vol. 2, p. 423. Sabellaria A„ 

 Quarterly Journal of Science, vol. 14, pi. 3, fig. 4. Mont. 

 Test. Brit., vol. 2, p. 540. Clustered Sand Tube. Com- 

 mon, and in favourable situations increasing so as to cover 

 a large extent of rock ; over which it is impossible to walk 

 without crushing multitudes of these frail habitations. The 

 situation chosen may not at first sight appear the best, for a 

 creature which requires a considerable quantity of sand, 

 before it can be provided with an habitation, which is 

 placed on the bare rock, at the distance of many feet, or 

 even yards, from the materials. But a bed of sand, 

 though affording materials, would prove a bad foundation 

 for the structure. Trusting therefore to the waves for 

 what they may bring within reach, the building is placed 

 on the elevated surface, and the most successful season ot 

 erection is in stormy weather. In the first stage of exis- 

 tence, and when only a single tube is produced, the 

 appearance of this tube is much like that of Vermilia Tri- 

 quetra, except in the nature of the materials employed. 

 The orifices of the subsequent formations are more 

 rounded and turned up. 



Reasons have been given why animals of this and the 

 following genus should be excluded from a work which treats 

 only of shells and their molluscous inhabitants ; since these 

 resemble the latter in no respect, and the former only re- 

 motely. But faint as is the likeness, it is not altogether 

 visionary, and as it tends to show the links through which 

 the affinities of nature are continued, it deserves our atten- 

 tion. The Arenicolae, as Cuvier terms them, are not the 

 only creatures in which there is no adhesive attachment 

 between the case and its inhabitant. But the process of 

 construction of these slightly organized habitations is not 

 exceedingly remote from that of the most complete and 

 beautiful of testaceous structures. In the latter, for the 

 purpose of growth, the mantle is applied to the surface of 

 the structure, even beyond tho portion to which it actually 

 adheres; and the exudation of carbonate of lime with 

 animal matter, is plastered on it. But in the case of the 

 present family, the process is so far different, that animal 

 gluten aloua is poured out; and this being fashioned iutu 



