RATTULID.E. 69 



This species has manifest affinity with porcellus ; but it is much slenderer, and its 

 proportions are different. The width of the body to its length (exclusive of the foot) is 

 as 1 : 4 ; whereas in porcellus it is as 1 : 2. The toe is here beset with a short sub-style 

 on each side (as in Mastigocerca] ; whereas in porcellus I can see no trace of these. 

 The lorica, moreover, is not elevated into any sensible dorsal ridge. In all other re- 

 spects it appears to agree with the preceding, except in being somewhat longer. 



The species first occurred to my notice in water from Woolston Pond, sent me in 

 September by the courtesy of Miss Davies. Several examples occurred, but all dead. 

 A few days later I found it alive in water sent by Mr. Bolton from Birmingham, as well 

 as another dead. P.H.G.] 



Length, T ^ to r l f inch ; depth, ^J^ to -^ inch. Habitat. Weedy pools. Wool- 

 ston : Button Park and Coleshill, Birmingham (P.H.G.). 



C. BEACHYUBUS, 



(PI. XX. fig. 21.) 



Monocerca brachyura . . . Gosse, Ann. and Mag. Nat. Hist- Sept. 1851. 



[SP. CH. Body cyUndric, short, plump, decurved ; lorica not ridged; head witlwut 

 spines ; toe-length less than the depth of the body. 



This species I described in 1851 from a single example taken on Hampstead Heath. 

 It died before I had completed my observations ; but I have since seen it on repeated 

 occasions, from various localities, though always scarce. With much resemblance to 

 C. porcellus, it is notably smaller ; there is no trace of ridge ; the twofold toe, though 

 exactly similar, is proportionally shorter ; the front is obtusely truncate, seen dorsally 

 and laterally, and is destitute of projecting spines. When viewed endwise (as on many 

 occasions), the transverse outline appears quite circular, so far as the back and sides are 

 concerned. A long depending brain carries a great red eye at its tip. The singular 

 appearance of a second eye in the breast, mentioned in my original diagnosis, occurred 

 in no other specimen ; it must have been illusory, though unaccountable. The viscera 

 agree with those of porcellus ; the contractile vesicle very large. The toes are almost 

 always thrust up under the belly. 



In manners this varies much from its lively predecessor, for though constantly in 

 motion it is singularly slow and sluggish, creeping to and fro on the leaves of the 

 milfoil, nibbling ever as it goes. P.H.G.] 



Length (without toe), T ]^ inch ; toe, 7 J- - inch ; total, r ^ inch. Habitat. Hampstead 

 Heath ; Sandhurst ; Woolston ; Caversham (P.H.G.) : pools : rare. 



C. CAVIA, Gosse, sp. nov. 

 (PI. XX. fig. 22.) 



[SP. CH. Body elevated and globose, very protuberant behind the foot; lorica 

 ivithout ridge or frontal spines. 



In the summer of 1885 Mr. Henry Davis kindly collected water for me near Snares- 

 brook in Epping Forest. Among other treasures found therein I me t t with this pretty 

 little creature, which at first I was inclined to identify with C. brachyurus. It differs 

 from it in form, however ; the great elevation of its hinder quarters, and particularly the 

 development of its buttock into a great plump breech, gives it the aspect of a squatting 

 mouse or guinea-pig, and makes the double curved toe proceed (in appearance) from a 

 notch in the belly, far forward. The mastax agrees with that of its congeners, of 

 moderate size ; but the brain is very large, and so is the eye at its point. The stomach 

 was ample, filled with yellow food. Face truncate, slightly prone. The little thing was 

 rather swift at first, but not wild. P. E.G.] 



Length (without toe), ^i inch. Habitat. Epping Forest (P.H.G.). 



