BLOOMER : ANATOMY OF CEKATISOLEN AND SOLECURTUS. 37 



portion of the iiitestiual wall. It then returns along, and connected with 

 the right dorsal side of the caecum for about two-thirds the length of the 

 latter, when, becoming free, it makes a few folds and the typhlosole dis- 

 appears. The intestine then makes a large number of irregular folds, and 

 continuing as the rectum passes through the ventricle, shortly reaches the 

 posterior adductor muscle, passes closely round it, and returning a 

 short distance along the ventral surface, terminates in a large bilobed anus 

 having a circular appearance (Fig. 4, A.). 



The crystalline style (Figs. G & 7, C. S.) fills the greater part of the 

 caecum, and extends to the anterior portion of the stomach. 



The tricuspid body occupies the centre of the stomach, and has branches 

 radiating into the different divisions. 



A transverse section across the caecum of the crystalline style and 

 the intestine of Solecurtus candidus (Fig. 7), shows the former to be lined 

 with a columnar epithelium {Ep. Col.), carrying a dense fringe of long 

 cilia, the nuclei are situated with regularity near the centre of the cells a 

 little closer to the base than the free end ; while the latter — the intestine — 

 is lined with an epithelium {Ep. C), consisting of short ciliated cells, broad, 

 and chiefly connected Avitli each other at the free end, narrowing towards the 

 base, and having undeveloped cells and spaces between. The division of 

 the caecum from the intestine is marked by a constriction of the enveloping 

 muscular layer. On the one side the columnar epithelium passes inside 

 this constricted part and a short distance along the side of the intestine, 

 gradually merging into the intestinal epithelium. On the opposite side, 

 however, occurs a curious growth {Ep. U'.), Avhere the epithehum consists 

 of very long cells of uniform width, and passing from the base to the free 

 end in a slight wave-like course, the nuclei being abundant and situated 

 in the basal portion of the cells. It, liowever, ends abruptly at the point 

 where the wall projects farthest into the lumen, marking on this side the 

 division between the caecum and the intestine, and the smaller intestinal 

 cells then follow ; on the other side of it the cells gradually decrease in length, 

 until they merge into the ordinary columnar epithelium of the caecum, 

 The cilia on this curious growth of epithelium are scanty and short, and 

 near the intestinal cells ^ apparently altogether disappear^. In this latter 

 part there is a break in the epithelium (Ep. B.), which continues through 

 a number of sections, and then the epithelium resumes its normal condition. 

 It is probably a duct communicating with the gland .underneath the 

 epithelium. It may be remarked this curious piece of epithelium closely 

 resembles tliat described by Johnstone in CardiumP' 



The liver or digestive gland (Fig. 4, L) is a large organ surrounding 

 the stomach, with the exception of a small portion of the dorsal and pos- 

 terior parts. The large bile duct enters the stomach on the ventral surface, 



/;" 



Caicliuni, Liverpool Marine biological Committee Jlemoirs. 



