X()'i'():\iMArAii.i':. 17 



rotatory organs to be wanting. Yet, lately 1 saw one on whose front a strong ciliary 

 action was conspicuous : it seemed as if the ciliato surface were on the prone side of the 

 front. The species, moreover, is furnished with protrusile auricles for augmented loco- 

 motion, like Notommata proper. I have not myself seen these, indeed ; but the fact rests 

 on ample evidence. Dr. Hudson was assured by Mr. Hrayley, the Secretary of the Bristol 

 I\IicroKCopical Society, that he had seen a Taphracainpa " put out very small aiu-icles 

 from the head, and swim with a slight vermiform movement." He had made a pen-and- 

 ink sketch of the creature in both conditions ; which sketch is in my possession, and 

 represents indubitably T. annulosa. Miss Saunders, too, a careful observer, writes mo 

 under date of June 10 : " Watching your Taphrocampa annulosa a long time, I saw it 

 thrust out an ear-like lobe on each side, and swim frantically about in a most heiullong 

 fashion ; but only one of three did this. The processes were not very prominent, but 

 Mi're quite distinct." This fact aft'ords an interesting link with the present family. 



The form of the nuistax and trophi, too, though not yet quite satisfactorily defined, 

 is evidently Notciiiniatoiis, and seems to resendile the pattern seen in some of the Fur- 

 ctilariie, ami some of the Battnliihe also, consisting of an inc\is with a long lulcrum and 

 n pair of long incurved mallei. The animal can bring the tips of the jaws to the v(^ry 

 front, and nibbles floccose matters with them. An alimentary canal, broad and straight, 

 with no accessory glands, and with no constriction, runs through the cavity to the cloaca 

 close to the foi'ked toes. It is usually empty and colomdess. At the occiput, behind the 

 mastax, and almost invariably sharing its motions in contraction and (dongation, is a 

 moderate- sized mass of opaque matter, white by reflected light, and probably chalky. 

 Like a similar mass in many NotommaUe, with which it is another link, it lies at the 

 bottom of a wide and deep sac. I had vainly searched for any trace of red pigment in 

 this mass which might indicate an eye. On one occasion recently, however, I was 

 examining a specimen under direct sun-light, wlii'u there suddenly fhished out from the 

 opa(]ue mass a spark of radiance, as if from an cye-lcns, though 1 could not discern any 

 nnl hue. What represents the ordinary foot and toes is peculiar. It would seem rather 

 to be a forked tail ; for I have seen, lunv and then, projecting benea,th this, a very 

 delicate rounded lobe, which is possibly the foot, the cloaca opening between these. Or, 

 rather, it is the optical expression of the lower half of the cylindrical rectum, of which 

 the middle of the crescentic fork forms the upper part or ceiling. The intestine can be 

 traced down to this orifice beneath the fork. The fork, or, if this explanation is correct, 

 the tail, is formed of two incurved taper, chitinous, clear, sharp spines, together making 

 a semicircle ; but not separated into toes, nor articulated with the segment that carries 

 them, and so having no power of motion ind<>pendent of one another, or ot their 

 segment. 'I'rue toes would have both. 



The animal contracts strongly a,nd continually , like a Notoiinnala ; hut the sphere of 

 the contraction is the space occupied by the alimentary canal, the parts both before and 

 behind this viscus remaining unafl'ected, while the pai-ts included contract forcibly, and 

 both ways, but chiefly from behind forward. In most of its movements it resembles 

 C7/(V!^r)»f)/»,s-, crawling sluggishly about the glass, and the masses of sediment.' — P. H.G.J 



Length. About -, J,„ hich. Habitat. Pools and ditches : common (P. H.G.). /"^i")// 



' Thorp (ire two very tlistinet \aii(>tieK of tlic above, woll-niarlted and coiiRtaiit ; yd witli harflly 

 flufiicient dissimilarity to warrant our separating them as species. The one smaller, with the aitieula- 

 tion stronR, the lateral projections of dark tissue into each segment clearly seen, the caudal points 

 short, stout, and stniiijht. This was the form (irst recoKnized, is the form above described, and is by 

 far the more common. The other much larger, the articulation and the interior projections both in- 

 distinct, often imperceptible ; the caudal points long, slender, crescentic, wider at their bases, and 

 making together a regular semicircle. In this variety, an excellent observation which I obtained 

 showed the mnntar, mallei, and incus, almost exactly of the same familiar )iMtlern as in h'nioiiimnia 

 utirila {Phil. Trans. 18,'j(j, pi. xvi. figs. 1(;-21). 



VOL. II. 



