22 



Art. 3,— T. Kaburaki 



n'^ 



A^^ 



. br 



c 



_1 — -jik 



. nh 



--9n 



Text tig 1. Frocerodes lactea. Diagram- 

 matic representation of the organization 

 of an entire worm, as seen from the dorsal 

 side. 



br brain, e eye, g gut, (ij) genital pore, m 

 mouth, N^-X^' sensory neives arising from 

 the brain, nt longitudinal nerve trunk, o 

 ovary, od oviduct, ph pharynx, ps penis- 

 shtath, fs receptaci^lvim sremins, te testis. 

 rd vas deferens. 



it is subject to variatioDs to some- 

 extent in different species and 

 genera. 



Brain. — Pr. lactea {Taxi fig. 

 1). The brain is formed on the 

 same plan as that of Pr. idvae. 

 Each half, connected with its 

 fellow b}" three strong commis- 

 sures, is nearly of a pyramidal 

 shape, and consists, as usual, of 

 three ganglia. From each brain 

 mass arise some six sensory 

 nerves directed forwaidly and 

 laterally. The inneimost nerve 

 (N^). taking its origin at the 

 anterior corner of the brain 

 mass, proceeds forwards on the 

 ventral side just inside the 

 dermal musculature. Laterally 

 following to this is present the 

 second ner\'e (iV^^) which pro- 

 ceeds forwards and appears to 

 stand in connexion with the 

 dorsal longitudinal trunk on the 

 marginal nei"ve, nmch as in Pr. 

 vlvae. The following third and 

 fourtli nerves {]S^^^. iV^' ) branch 

 repeated^ and extend anteriorly 

 to the tentacular region. Be- 

 sides, among the other two 

 sensory nerves given off fi-om 

 the lateral part of tlie brain 

 mass, the anterior (xV ) pursues 

 a course laterally directed, and 

 the posterior reach tbe eye. 

 Furthermore, immediately below 



