128 Transactions. — Zoology. 



comes a perfectly enormous stomach, filling up nearly all the 

 great circular body. It is filled with a great quantity of food- 

 matter rolled up in little balls (fig. xii.rt.), and varying in 

 colour from dark-brown to dark-yellow. The specimen figured 

 bears three eggs, but, in the other I saw, the whole body-space 

 was filled with food. The intestine rather iudistincily leads 

 round from the posterior part of the body to the ventral side, 

 and so to the junction of the foot and the body. The muscu- 

 lature is faint, but some distinct strands mav be seen in the 

 flexible foot. No glands of any kind were observed. The 

 only sense-organ is the eye. It is placed cervically, near the 

 dorsal part of the body, and is wedge- or pyramid- shaped, 

 with the apex pointing downward. It is of the usual red 

 colour. No bram could be observed. In one specimen three 

 large pink-tinted eggs, already segmented, were situated over 

 the orifice of the foot. 



The two specimens that I found were both very sluggish ; 

 I rather fancy one died while I was observing it, while the 

 other never moved out of its place ; so that of the movements 

 of this Salpinidaean I can say almost nothing. It extended 

 and retracted its head and foot with great frequency, and 

 sometimes waved its cilia vigorously, sometimes held them 

 still, but that is all I can say. 



Both specimens occurred on the same slide, and were 

 secured from the sn:all pool. 



Family CoLURiDiE. 



Genus Colurus, Ehrenberg. 



Generic characteristics : Body subglobose, more or less 

 compressed. Lorica of two lateral plates, open in front, 

 united on the back, gaping behind and (in general) wholly so 

 up the belly. Frontal hood in form of a hook, not retractile. 

 Foot permanently extruded, of distinct joints, terminated by 

 two furcate toes. 



XIII. Colurus gracilis, sp. nov. Plate XL, figs, xiii., xiii.a., 



xiii.&. 



Specific characters : Lorica in dorsal aspect most grace- 

 fully oval. A very slight anterior and posterior dorsal fissure. 

 Ventrally the two lorical plates approach each other in the 

 middle of the ventral line, and then sw^eep away from each 

 other both posteriorly and anteriorly in an easy graceful curve. 

 Oval in lateral aspect. Foot of three joints, half as long as 

 body, pendent from a point a quarter of the way from posterior 

 body. No eyes. 



Absolutely no colour. As this, with the other Coluridce, 

 is compressed, it usually swims on its side, and then presents 

 an oval outline, the greatest breadth of the oval being just 



