62G 



BRANCHIPUS BRASS1A. 



number from twenty to more than a hundred, being 

 flattened, the joints forming ciliated plates. They 

 have a pair of eyes, and the antennae, of which there 

 is generally only a single pair, are small and not fitted 

 for swimming. This section is divided into two prin- 

 cipal groups. 1. The Ceratopthalma, having the eyes 

 generally carried upon footstalks, ten or twenty-two 

 pairs of legs, the anterior neither much longer than 

 the remainder nor branched. The eggs are either 

 internal or carried in a sac at the base of the abdomen 

 (Limnadia. Branchipus). 2. The Aspidiphora, having 

 sixty pairs of legs, all furnished at the base with a 

 vesicle, the anterior very large and ramose, three 

 sessile eyes, with two bivalve capsules enclosing the 

 eggs, and attached to the eleventh pair of legs ( Arus, 

 which see). It is to be observed that the subdivisions 

 of this order have been regarded by Messrs. Strauss, 

 Edwards, and some other authors, as separate orders. 

 BRANCHIPUS (Latreille; CHIROCEPHALUS, 

 Jur.). A genus of crustaceous animals belonging to the 

 order Branchiopoda, section Phyllopoda, and group 

 Ceratopthalma. In this remarkable genus the eyes 

 are placed at the extremity of footstalks, the body is 

 narrow, long, and compressed, the head distinct, with 

 two horns between the eyes, eleven pair of legs, the 

 abdomen long and cylindric, with two terminal ciliated 

 plates. The males are distinguished by a pair of very 

 large horns attached to the mouth. The eggs are 

 borne by the females in a pouch attached to the base 

 of the abdomen. Jurine, Prevost, and Dr. Shaw 

 have given very full accounts of the structure and 

 habits of these animals, of which we have met with 

 one of the species, which are few in number, in stand- 

 ing water, near Turnham Green. When full grown 

 they are about an inch and a half long, and are found 

 occasionally in great numbers in small puddles of 

 standing fresh water ; indeed, like the species of apus, 

 they are often to be observed in water collected after 

 heavy rain, especially in spring and autumn. They 

 swim well upon their backs, and their legs, which are 

 incapable of assisting locomotion, are kept in constant 

 undulatory movement, which has for its object the 

 forming of a current of water between the base of 

 these organs, and which, following the canal of the 

 breast, conveys to the mouth the small particles upon 

 which the animal feeds. Its movements are caused 

 by repeated jerks of the tail ; so that when swimming 

 upon its belly it appears just like a small fish. The 

 eggs are yellowish coloured ; they are at first round, 

 but afterwards assume an angular form, which favours 

 their preservation, since it appears that they are 

 enabled to withstand a very considerable degree of 

 drought until a fall of rain sufficient to cause them to 

 hatch takes place. The females deposit their eggs 

 at different times to the number of from one to four 

 hundred at each time. On quitting the egg the body 

 is divided into two globular masses, the anterior of 

 which comprises a single eye, two short antennae, two 

 large branched organs serving for swimming, and two 

 short and slender legs. After shedding their skin 

 the first time, they have three eyes, the middle one 

 being smooth; the hinder part of the body is elongated, 

 and the tail is terminated by two short filaments. 

 Subsequently the legs begin to appear by degrees, 

 and the branched organs entirely disappear. 



Dr. Leach established a genus intimately allied to 

 the preceding under the name of Artemia, for the re- 

 ception of a small but interesting species, of which an 

 account was first given in the eleventh volume of the 



Linna?an Transactions, by Mr. Racket, and named 

 by him Cancer salinus, or the brine shrimp. During 



Brine Shrimp. 



the past year (1834) Mr. J. V, Thompson has pub- 

 lished a very interesting notice of it in his Zoolo- 

 gical Researches, accompanied by numerous figures. 

 The body is oval, and flattened, with the head not 

 separated from it ; the tail or abdomen is long, ter- 

 minated by two small points. " The brine shrimp, 

 or Artemia" (not Artemis, as Mr. Thompson, from 

 whom we quote the following observations, calls it) 

 " salinus, is a very small and delicate animal ; when 

 full grown about half an inch in length, of consider- 

 able transparency, slightly tinged with yellow, and 

 with a highly polished surface ; nature having con- 

 structed them with members solely adapted to swim- 

 ming, they seem to be in perpetual pursuit of prey, 

 gliding with an almost even motion through the water, 

 and moving with equal indifference and facility on 

 the back, belly, or sides; the shape of the animal, the 

 undulating movement of its fins, and the glossy appear- 

 ance of its coat render it an object of a very interest- 

 ing description, more especially when apprised, that 

 analogous animals appear to have been the first 

 created conspicuous inhabitants of the primitive fluid, 

 of which these may be regarded as a degenerate or 

 pigmy race. Hitherto the only localities in which 

 these little animals have been observed are some salt 

 lakes in Siberia, and the salt-pans at Lymington, 

 Hampshire ; in these situations, however, they oecur 

 in the greatest abundance ; and at the last named 

 place, making their appearance in the early part of 

 the spring, multiplying beyond conception during the 

 summer and autumn, and disappearing during the 

 winter months, a phenomenon common to many of 

 the smaller Crustacea. As in all salt-works the pits 

 have different distinctions, it must be observed that, 

 they are not found indiscriminately in all, but princi- 

 pally in the tanks, called clearers, in which the brine 

 acquires such strength as to furnish four ounces of 

 salt to the pint measure ; by the account with which 

 Mr. Racket has favoured us, it would appear that the 

 workmen attribute to them the property of assisting 

 in the clearing of the brine, and hence transport them 

 to such tanks as seem to be without them. How 

 they came originally to the salterns at Lymington, 

 and what animalcula live in so strong a solution to 

 afford them food, must be left to future investigators 

 placed under more favourable circumstances." Mr. 

 Thompson has traced the gradual development of 

 these curious animals, which nearly resemble those of 

 the branchipus. 



BRASSIA (R. Brown). Named in honour of 

 W. Brass, a botanical collector. It belongs to the 

 curious order, Orchideoe, and is one of the most 

 beautiful of the tribe. The two species at present 

 known are, B. maculata, has large pale yellow flowers ; 

 spotted with brown ; B. caudata has similar flowers, 



