810 RECORD or CURRENT RESEARCHES RELATING TO 



of the bocly-siibstancc wticli extends into the tentacle here loses its 

 granular character, and is simply hyaline. The tentacle is of equal 

 length as far as the tuft of cirrhi ; it is flattened. The colourless 

 cirrhi have the form of pine-needles, are • 03 mm. long, and occur to 

 the number of thirty or more; in the extended state of the tentacle 

 they are inserted along one-fifth of its length ; in contraction they are 

 reduced to a mere tuft. They are firmly attached, and, like the rest 

 of the organism, resist the action of ordinary reagents. Contraction 

 and elongation take place in the tentacle at intervals of two minutes ; 

 the cirrhi move rapidly at the same time, either by bending or other- 

 wise, but not after the manner of either cilia or flagella. No use was 

 observed to be made of these movements for prehension of food, which 

 M. Eobin has never noticed taken into the body. 



The affinity of the animal is with Acinetopsis rara. The cirrhi 

 can hardly act as suckers, as Claparede supposes, for they are flattened 

 and more mobile than the suckers of the Acinetines, and terminate 

 neither in a point nor a swelling as in those forms. 



Worm parasitic on Ophryodendron (Fig. 2). A vermiform body (/) 

 sometimes occurs, rooted to the body of the animal, which has been 

 supposed by Claparede to be a species or stage fif the same animal, 

 and in which he wrongly figures trichocysts ; Wright took it to be 

 either a bud or one of the Gregarinida. It is, however, M. Eobin 

 considers, a larva of some worm ; its tissues differ in character from 

 those of Opliryodendron ; it is separable from it without rujiture, and 

 is fixed by a special attaching organ ; it wants the nucleus and vacuole 

 of the Gregarina3. The basal organ of attachment [j, k) consists of a 

 slender chitinous rod embedded in the worm, with five or six short 

 hooks which penetrate beneath the cuticle of its host near the 

 tentacle. The body is greyish and finely granular, and is transjjarent 

 at the anterior end, which has a sucker -like enlargement ; the prox- 

 imal end bears an oblique disk-like surface ; dilute hydrochloric 

 acid causes its substance to shrink and expose a homogeneous cuticle 

 to view. It moves slowly round on its peduncle, and resembles in 

 some points the filarian larvae of many Nematode worms. 



Acinetopsis rara sp. n. (Fig. 3), discovered by M. Eobin at Con- 

 carneau, is also a tentaculate Infusorium. It occurs attached to 

 Sertularians, is from '07- '09 mm. long, and two-thirds as broad, 

 and lives in a wine-glass-shaped theca (b, c), which rests on a very 

 slender peduncle (a), 1 mm. long. The body is uniformly granular, 

 greyish, with a small contractile vesicle ; upper surface flat, an alter- 

 nately extended contractile tentacle (d, e) proceeding from its centre. 

 The tentacle, which measures 1 mm. or more in length by * 004- • 005 

 mm. in thickness, is of uniform thickness throughout, and colourless, 

 homogeneous, and transparent ; by contraction it is reduced to a length 

 of 'OS-- 08 mm., with a breadth of '01 mm., becomes marked by 

 transverse striae, and is now seen to consist of a central filament, 

 surrounded by a spirally plicated membrane (/). In extension, it is 

 capable of movement in all directions. The shell or theca is continuous 

 with the substance of the i)eduncle, and is delicate, colourless, flexible, 

 and has a free circular edge, beyond which the body is never pro- 



