Cr.ADOCERA.- 



-CRUSTACEA.- 



-PlECII.OPODA. 



291 



and thus ailapted more for respiration tlian looomotion. 

 Tho body is usually divided into numerous segments. 

 This order contains the largest individuals of all the 

 JDntoraostraca, and many of them tho most remark- 

 able for beauty. As an ilhistratiou of the order, we 

 have annexed a figure of Cliiroccphahis diaphaniis. — 

 See fig; 192. 



Okder II.-CLADOCERA. 



The species of this order are generally very 

 small and have the body, with the exception of 

 the head, contained within a delicate trans- 

 parent carapace, formed in the shape of two 

 valves joined together on the back. They 

 possess from four to six foliaceous branchial 

 feet, have only one eye, and two pairs of 

 antenna;, tlie lower of which are tho organs of 

 motion. 



The species here represented (fig. 193) is 

 Dajihnia Sdiccffcri. 



There are seven known British species; that figured 

 is by far the largest of the family, being about the 

 fifth of an inch in length, and two linos broad. Their 



motion through the water is peculiar, being a tumbling, 



Fig. 103. 



j^V-.- 



Daplinia Schfpfferi. 



Iioavy sort of movement, and when seen in their native 

 ponds they seem to keep near tho bottom. 



Section II.— LOPnYKOPODA. 



The Lophyropods are characterized by their feet being 

 essentially organs of locomotion, and not branchials. 



Cypridina M'Andrei. Cyclops qimdriconiis. 



These are few in number, and are composed of several 



articulations of a more or less cylindrical form, which 

 are furnished with a scries of stiff hairs or set(P.. Their 

 branchia; or gills are attached to the organs of the mouth 

 and are few in number. The body is either completely 

 inclosed within a carapace exactly resembling a bivalve 

 shell, or partially covered by an envelope shaped like a 

 shield or buckler. The two forms constitute two onlers, 



OSTRACODA and COPEPODA. 



The first order, or Ostracods, we illustrate by a figure 

 of Cypridina M^ Andrei (fig. 194) ; the second (the 

 Copepods) by Cyclnps quadricornis (fig. 195). 



Very little is known of the habits and manners of 

 these interesting and curious little creatures; the two 

 species which have been found in Great Britain belong- 

 ing to this genus were dredged by Mr. M'Andrew 

 from a considerable depth. Cypridina M'Atidrei was 

 dredged in seventy fathoms, between the islands of 

 Lewis and Skye. Other species, C. Bronda, was 

 found in from eighty to ninety fathoms sand, twenty 

 miles east of the Noss, in the Shetland Islands. 



Section III.— PCECILOPODA (Parasitic Crustacea). 



The animals belonging to this section have the organs 

 of tho mouth adapted for suction, and not mastication. 

 They live a parasitic life upon aquatic animals, such as 

 fishes, &c.; and their mouth therefore is constructed so 

 .ns to accommodate them to their habitations and man- 

 ner of life. Their body is for the greater part inclosed 

 within a buckler-shaped shell or carapace of a horny 

 substance ; and their feet, which are in the greater num- 



ber, four pairs, arc partly adapted for enabling them to 

 walk with, and partly serve lor the purpose of respira- 

 tion, having branchiae or gills attached to them. When 

 young they are free and unattached, and do not resem- 

 lile in the least their parents. As they advance in life 

 they undergo a series of changes, and become attached 

 to various other animals. Many of them at last become 

 so transformed that they lose their eyes and feet, and 



