164 Mr. C. Spence Bate on the Nidification of Crustacea. 



case several specimens of Amphito'e rubricata wliicli I dredged up 

 at the east end of the Plymouth Breakwater. These varied in 

 their ages, from the very young to the well-advanced adult. In 

 the small tank they soon separated themselves, and remained 

 at rest in the same place. In these places I found that they 

 shortly constructed for themselves nests which appeared to have 

 been formed partly of foreign materials and partly secreted by 

 the animal. A small area around each lair was swept clean, as 

 if, in building, the animal procured all the material within its 

 reach. And it is highly probable that the quantity of secreted 

 matter is regulated by the greater or less amount of building 

 material at hand. We know, in the Spider, that after con- 

 structing one or two webs, its power becomes exhausted. It is 

 therefore desirable that they should economize this capability as 

 much as possible. The Amphito'e generally seek out well- 

 sheltered crevices at the roots of the great Laminaria (PL VIII. 

 fig. 5), under stones and other objects that break the wash of the 

 sea, and there construct abodes for themselves, by scratching 

 together any available material within reach, and uniting it into 

 a mass by a substance which they secrete. 



If we take one of these small nests, and place it under a 

 microscope, we find that it consists, independently of the col- 

 lected material, of a quantity of fine threads, closely woven and 

 knit together, crossing each other in the utmost confusion ; and 

 here and there are seen loops formed by a single thread being 

 doubled and spirally twisted upon itself (PL VIII. fig. 5 a), 



Mr. Thompson of Belfast has recorded having taken the com- 

 mon shore Amphito'e {A. littorina) in a nest; this I have seen, 

 but have had no opportunity of examining its minute structure. 

 It appeared to be more membranous than that of A. rubricata, 

 and to be constructed without any foreign materials*. 



The Podocerus is the next genus with which we are acquainted 

 as possessing this power. A summer or two since, Mr. Howard 

 Stewart brought me a small bunch of Laomedea, in the branches 

 of which a colony of P. pulchellus had taken up their abode. 

 The nests in this batch assumed a more decided form than those 

 of any other species that I have seen. The form of the nest was 

 narrow at the lower extremity and broad at the upper, at which 

 end, moreover, was an opening into the nest. The top was 

 covered, dome-shaped, except that it somewhat overhung on the 

 side over the entrance to the nest, giving a curved appearance 



* Since the above was written, I have received, among other Crustacea, 

 a specimen of Amphito'e littorina and its case from Professor Kinahan, of 

 DubUn. This was constructed of bits of weed, sand, &c., bound together 

 by fine threads, similar to that of A. rubricata. I could perceive no spiral 

 loops as shown in PI. VIII. fig. 5 a. 



