HISTORY OF THE SUBJECT. 21 



I. Fam. Nemertina. 



Mouth inferior ; anus terminal. 



(1) Body filiform, equally attenuated at either extremity (head indistinct) ; no respiratory 



fissures. 



a. Mouth and ovaria or testicles considerably removed from the snout. 



Genus 1. Cephalotlirix. 



b. Mouth and ovaria or testicles not much removed from the snout. 



Genus 2. Astemma. 



(2) Body linear, rounded, more or less dilated anteriorly (head distinct), respiratory fissures 



distinct or none. 



a. Head distinguished from the body, no respiratory fissures. 



Genus 3. Borlasia. 



b. Head not distinguished by a constriction from the rest of the body, respiratory 



fissures more or less distinct. 



a. Eyes in groups. Genus 4. Folystemma. 

 /3. Eyes 8 — 16, biserial. Genus 5. Nemertes. 

 y. Eyes 4. Genus 6. Tetr astemma. 



(3) Body linear-oblong, flattened, equally obtuse at either extremity, respiratory fissures 



distinct. Genus 7. Cerebratulus. 



II. Fam. Amphiporina. 



Aperture of the alimentary tube terminal. Genus 8. Ampldporus. 



The foregoing classification, being founded on external appearances, could not be expected 

 to stand, the more so as the writer's knowledge of the anatomy of the groups was imperfect. 



In this author's ' Inaugural Dissertation' 1 (for M.A.), published about the same time, 

 mention is made of the Nemerteans and other marine animals occurring in the Sound — in the 

 various zones, viz. those of the Trochi, Gynmobranchs and Buccini (corresponding with the 

 Littoral, Lamiuarian and Coralline of Eorbes). Little or no additional information on the 

 subject is obtained in this work, mainly on account of the difficulty in recognising his species. 

 He does not note the presence of any in the Laminarian zone. 



Mr. H. Goodsir, in 1845, made some remarks on certain of the Anopla, viz. Serpentaria 

 fragilis and "Nemertes gracilis" but his observations are characterised by serious structural defects, 

 apparently from too limited observations. 2 He termed the nerve-ganglia and cords the testicles, 

 and this upon the faith of his microscopic researches. He considered the alimentary canal, again, 

 a space common to the respiratory, digestive, and generative systems ; his digestive tract being the 

 proboscis. He thought that in Serpentaria each of the "annuli/' or fragments, contained all 

 the elements of the perfect or original animal, viz. a male and female generative apparatus, the 



1 ' De regionibus marinis.' Havnise, 1844. 



2 "Descriptions of some Gigantic Forms of Invertebrate Animals from the Coast of Scotland," 

 < Ann. Nat. Hist./ vol. xv, p. 337, pi. 20, f. 1—3. 1845. 



