The below mentioned article provides biology notes on Phylum Hemichordata. (Gk. hemi- half, chordate- notochord) Due to some similarities with chordates, some workers considered Hemichordata as a subphylum under phylum chordata. But, on grounds of its general organization, recent scientists, like Vander Horst (1939), Dawyd off (1948), Marcus (1958) and Hyman (1959), have given it the status of a phylum [...]
In this article we will discuss about the meaning and classification of phylum hemichordata. Meaning of Phylum Hemichordata: The animals with notochord constitute the Phylum Chordata. It has a major subdivision, called the Vertebrata or Craniata for possession of vertebral column or cranium. The rest of chordates, namely Hemichordata, Urochordata and Cephalochordata are collectively called the Primitive Chordates or Protochordates. [...]
In this article we will discuss about Balanoglossus:- 1. Derivation of Balanoglossus 2. Geographical Distribution of Balanoglossus 3. Habit and Habitat 4. External Structures 5. Body Wall 6. Supporting Structures 7. Locomotion 8. Coelom 9. Digestive and Respiratory Systems 10. Circulatory System 11. Excretory System 12. Nervous System 13. Reproductive System 14. Development 15. Affinities and Systematic Position. Contents: Derivation [...]