ZOOLOGY AND BOTANY, MICEOSCOPY. ETC. 457 



The nervous system is well developed, and consists of a cerebral 

 mass and a ventral medulla, which is closely associated with the 

 epidermis, and consists of two cords with a ganglionic layer ; on the 

 whole, the system is comparable to what is seen in the Archi- 

 annelids, save that it is segmented ; in every segment the two cords 

 are approximated or fused, and in the middle of the swelling the 

 ganglionic layer is sufficiently well developed to extend on to the 

 dorsal surface ; in the constrictions the cords are separated from one 

 another, and the ganglionic cells are small in number, or altogether 

 absent ; the swellings correspond to the segments as indicated exter- 

 nally, and to the " segmental organs." 



There are several sensory organs ; there are five anterior tentacles 

 which seem to have a tactile function, but they are not hollow as are 

 those of Saccocirrus, Polygordius, or Protodrilus ; on either side of the 

 dorsal surface of the head is a transverse ciliated pit ; each of the 

 hinder appendages have a small dorsal appendage which is ovoid in 

 form and has much the same structure as the cephalic tentacles ; there 

 are no eyes. 



The muscular system is of the same character as that of the 

 Archiannelids ; there are four pairs of locomotor appendages, two 

 anterior and two posterior ; they may be moved in all directions, and 

 are swollen at their free ends so as to be able to attach themselves to 

 foreign bodies. 



The renal organs are paired, lateral in position, and ciliated inter- 

 nally ; they are segmental, but there are nearly twice as many as 

 there are well-developed segments, for in the region of the generative 

 glands there are two pairs in each segment. Notwithstanding a 

 careful search the author was unable to detect any signs of a circu- 

 latory apparatus. 



The sexes are separate, and the presence of the glands causes a 

 dilatation of the posterior third of the body. There are two sym- 

 metrical ovaries, hardly distinguished anteriorly, but more or less 

 fused posteriorly. There are two sexual orifices on the ventral surface. 

 The coelom is small, is found in the head, and extends into the 

 appendages ; it appears to be an enteroccele. 



After a reference to the classification of the Annulata suggested 

 by Hatschek, which the author modifies by removing the Hirudinea, 

 which he regards as belonging to the Platyhelminths, and the 

 Gephyrea, the following scheme is propounded : — 



'1st order, Archiannelida I rr^ • -i -i-^ 

 ( Saccocirrida 



Annelida 



r> J J m. ,. 1 i (Archichfetopoda). 



2nd order, Ch^topoda l^oljch^i^. 



\ Oligochseta. 



Problematical Organ in CMoraemidae.* — -This is described by 

 Dr. R. Horst as a dark, tubular organ, lying above the oesophagus, 

 which is narrow anteriorly whilst it broadens posteriorly to meet 



* Zool. Anzeig., viii. (1885) pp. 12-5. 



