13 



begin directly behind the point where the salivary glands originate, and extend a considerable 

 distance distally. Any opening of these glands cannot be discerned (fig. 113). 



Fig. 43 shows that the pharyn.K distally from the radiila narrows considerably and 

 suddenly passes into the intestine, without first forming a separate oesophagus. The intestine 

 itself does not furni.sh much worthy of note; from my transverse .sections the folds are very 

 difficult to trace. The rectum opens out dorsally into the cloaca. 



With regard to the nervous system hardly anything can be mentioned, the state of 

 pre.servation not being such, as to admit of this. Sublingual ganglia cannot be indicated 

 with certainty. 



The genital glands only extend a little distance proximall)'. Genital products are not 

 present. The situation of the organs in the posterior part of the body is represented in the 

 reconstruction fig. 51. The cloaca-ducts take a normal course, unite and form the unpaired 

 precloacal-organ. Where they curve the cloaca-ducts are continued into a coecum, with the same 

 structure as the glandular jjortion of the precloacal-organ itself The appendages are remarkable. 

 First a long tube is observed at the end of which there is a pouch, stretching far distally and 

 situated against the body-w^all (fig. 5 i a). Into the part of the cloaca-ducts proceeding proximally a 

 small tube opens, leading into a specious pouch with attenuated wall (3), built up of cubical 

 epithelium. In neither of these appendages are spermatozoa found (cf. figs. 52 — 55). 



Two copulation-spicula occur in the cloaca (fig. 5it"-<'); they are long and run dorsally, 

 their ends being therefore situated dorsally to the rectum. They are not purely calcareous; 

 after decalcification there remains in the sheath a cuticular mass, having in many places round 

 openings, it being therefore cjuite possible, that not one large spiculum is found here, but 

 several smaller ones, situated next .to each other, a phenomenon we also remark in Paramenia 

 Pruvoti. (Pruvot 4 pag. 774). 



The heart is of a peculiar structure, though not ever\-thing about it is clear to me. 

 In fig. 56 some of the sections are represented. Beginning distally it is seen from A that the 

 dorsal pericardial wall is invaginated («), more proximally this invagination becomes bilobed, 

 and next to it another invagination originates (B, 6). Both a and fi unite and form one laro-e 

 invagination (C, /> ■ a), this portion of the heart being therefore in some degree trilobate. 

 D represents this portion of the heart, which has lost its connection with the pericardium-wall 

 more proximally and is King free in it. The shape is more or less triangular. More proximallv 

 still the heart divides into two halves (E.); both parts regain their connection with the dorsal 

 pericardial wall, and appear as invaginations of it. How to explain those different invaginations? 

 This cannot be done with certainty: a and /> might be atria. Ilut what may be the ventricle 

 in that case? If the invaginations c are to be taken for it, then the ventricle is distinctlv double, 

 which is possible, l)ut has not been met witli as yet. Then atria and ventricles would be .situated 

 the one behind the other, a situation also found elsewhere. Hut this interpretation cannot be 

 sustained with certainty, the structure of a, b and c being e.xactly alike. Only an accurate 

 comparison with other forms can procure us a good insight into this. 



What is indicated in fig. 56 A by d, also visible in the following figures is a peculiar 

 accumulation of cells, with large, oval nuclei, staining obviously. Probably these cells carrv cilia. 



