Sept. 1, 1870.1 



HARDWICKE'S SCIENCE-GOSSIP. 



201 



of metallic clink, which astonishes us the first time 

 we hear it proceeding from our aquarium. 



animation we find to be " rounded eminences 

 belonging to the cellular epidermis, and from which 



Fig-. 188. Polycera Lessonii, x 3. C. Barron, Ad. Nat. Delt. 



These very transparent and all but invisible 

 things, which we can only see 

 shooting about when the light 

 falls upon them, and which then 

 look very much like those little 

 glass tubes which ladies call 

 "bugles," and use in trimming 

 bonnets and dresses, are Sa- 

 gitta. There has been some 

 discussion respecting their 

 affinities ; they have been 

 classed with the marine anne- 

 lids ; but of late they have been 

 _G placed amongst the Articulata. 

 " The body olSarjitla hipunctata 

 is divided into three distinct 

 portions, — the head, the trunk, 

 and the caudal portion, which 

 are separated from each other 

 by transverse septa. Poste- 

 * riorly, the body is furnished 

 on the sides and extremity with 

 fine delicate membranous ex- 

 pansions, which have received 

 the name of fins, though bear- 

 ing no analogy with the fins of 

 a fish. The caudal fin is quite 

 distinct ; it is broad and some- 

 what rounded, expanding like a 

 fan from the posterior extremity 

 V, |fp ?— e of the body, and passing a short 



F ig. is9. s.bipunctata, distance upon each side." The 

 dorsal aspect, x 10. integument displays numerous 



distinct whitish well-defined spots, which on ex- 



project minute bundles of excessively delicate rigid 

 filaments or setae." The head is distinctly separate 

 from the trunk, and is surrounded by a sort of 

 membranous hood, which is capable of being drawn 

 backwards over it. On each side a series of curved 

 pointed hooks (fig. 190, c), which, when the hood 

 is expanded, close from either side of the mouth. 

 Besides these large buccal hooks, there will be ob- 

 served at the anterior extremity of the head two 

 curved series of smaller denticles (fig. 190, a), one 

 behind the other on either side. 



Fig. 190. Head of ditto, ventral aspect, x 25. 



Unfortunately, the whole of our specimens of this 

 genus caught on our preceding excursion died, and 

 we have thus been prevented from introducing an 

 original drawing from nature, which we had calcu- 

 lated upon ; but we have been fortunate in finding a 

 thoroughly reliable drawing in The Journal of 

 Microscopical Science, vol. iv., 1856, which fully 

 answers our purpose of enabling the novice to 



