zooLoor. . 23 



Order HIRUDINEA. 



A suctorial disk at one or both ends, by which progression is efi'ected. Most 

 species are aquatic, and many parasitical. 



Leeches both land and water are tolerably numerous in Burma, but have not 

 been specifically determined, and the same remark applies to the next order. 



Order OLIGOCHiETA. 



To this order belongs the family LumhricKhe, embracing the common earth 

 worms. 



Order CHJ^TOPODA. 



To this order belongs the family Arenicolidcc or common sea worms, as the 

 Arenicola pineal onmi, so useful for bait, which dwells in sand and sandy mud lietween 

 tidemarks on the English coast, and is doubtless represented by allied forms in 

 Burma. 



Order CErnALOBRANCHIA. 



To this order belongs the family Serpidita or marine worms, protected by 

 a shelly tube. These worms respire by branchiaj attached to th-e head, and the 

 tubes wherein they reside are either secreted by them, or built by the animal 

 agglutinating grains of sand together to form the tube wall. Many of them were 

 formerly regarded as mollusks. 



Order BOTIFEEA. 



Jlinute aquatic animals which TUidergo no metamoi-phosis, are rarely parasitical, 

 and have the sexes distinct. The name ' wheel animalcules ' is applied to them, from 

 the anterior end being furnished with one or more retractile disks bearing cilia, 

 which when vibrated produces the appearance of a wheel rotating. The Burmese 

 species are entirely uninvestigated. 



Class POLYZOA. 



This class, more commonly known as Bnjozoa or Corallines, are marine organisms 

 found in social colonies, some of which are often taken for seaweed, whilst others 

 spread over or encrust submerged objects. 



Sub-Kingdom V. ARTHROPODA. 



Segmented animals with distinctly jointed legs. Nervous system ganglionic. 

 Sexes usually separate. 



Class CRUSTACEA. 



Crustacea are remarkable for the metamorphoses through which they pass, 

 and it was long before the connexion was discovered between some of these larva 

 forms and the adult animal into which they developed. " Some of the lower forms 

 of Crustacea retrograde after passing the embryonic stage, but an advancing and 

 gradual metamorphosis is more general. Three larval forms may be distinguished. 

 1. Nauplius. Oval, unsegmented, one eye, three pairs of appendages, which are 

 converted into antenna; and gnathites (masticatory organs). 2. Zoea. Elongate, 

 segmented ; thorax with a dorsal spine, two sessile eyes, abdomen as long as the body, 

 legs rudimentary. 3. JSIegahipa. Flattened, segmented, no dorsal spine, two pedun- 

 culate eyes, abdomen much diminished, partially bent under the body ; five pairs of 

 legs " (I'ascoo, op. cit.). The lower crustaoea do not pass the .Zoert-stage, and some 

 go through the JVoM^/jMs-stage in the egg. 



Sub-class CIRRIPEDIA. 



Body inclosed in a carapace formed of many pieces. Feet in the form of cirri. 

 Sexes usually united in the same individual, but when distinct, the males are of 

 minute size and are epizoio or live on the bodies of the females. 



