COLPODA. 



[ 157 ] 



CONCRETIONS. 



perigonial leaves of Strelitzia regina the 

 yellow colour is said to depend upon the 

 presence of crescentic and curled filaments 

 floating in the cell-sap. 



The white patches upon variegated and 

 spotted leaves, such as those of Aucuba, 

 Holly, variegated Mint, Begonia argyrostig- 

 ma, &c., &c., arise from the absence of 

 chlorophyll in the cells subjacent to the 

 epidermis at those parts, which produces 

 the same effect as we see in leaves mined by 

 caterpillars. 



COLPODA, Schrank, Ehr.— A genus of 

 Infusoria, of the family Colpodea. 



Char. No eye-spot, tongue-like process 

 present, ventral sm-face ciliated, dorsal not. 



Dujardin says : " Body sinuous or notched 

 on one side, sometimes reniform, surface 

 reticulated or marked with nodular obliquely 

 interlacing striae ; mouth lateral, situated at 

 the bottom of the notch, and furnished with 

 a projecting lip. 



C. cucullus (PI. 24. fig. 25). Turgid, 

 slightly compressed, reniform, often nar- 

 rowed*^in front; length 1-1/20 to 1-280". 

 Common in vegetable infusions. Ecdysis 

 has been observed in this animalcule. 



Stein describes the encysting process and 

 reproduction from spores as occurring in 

 this infusorium. There can be little question, 

 however, that his observations apply to 

 Paramecium chrysalis, E> {Pleuronema chr., 

 Duj.). 



C. ? ren. Ovato-cylindrical, reniform, 

 rounded at the ends; aquatic; length 1-280". 



C. ? cucullio (Loxodes cue, Duj.). Com- 

 pressed, flat, elliptical, slightly sinuous in 

 front; aquatic; length 1-900''. 



BiBL. Ehr. Infus. 347; Duj. hifus. 478; 

 Stein, Infusionsth. 15, &c. 



COLPODEA,Ehr.— A family of Infusoria. 



Char. Gastric sacculi present ; no cara- 

 pace ; oral and anal orifices distinct, neither 

 at the ends of the body. 



Body usually covered with longitudinal 

 rows of cilia. The sacculi can be filled with 

 colom-ing matter. 



Genera : 



No eye-spot. 

 A tongue-like process. 



No cilia on the dorsal surface . . Colpoda. 

 Cilia on every part Paramecium, 



No tongue-like process. 



Body narrowed and prolonged in 



front(proboscis,E.),tailpresent Amphileptus. 

 Proboscis absent, tail present . . Uroglena. 



An eye-spot Ophryoglena. 



BiBL. Ehrenb. Infus. 345. 



COLURELLA, Bory, Duj. = Colurus, 

 Ehr. 



COLURUS, Ehr.— A genus of Rotatoria, 

 of the family Euchlanidota. 



Char. Two fi-ontal eye-spots ; tail-like foot 

 forked ; carapace cylindrical or compressed. 



Carapace openbeneath; cervical appendage 

 curved ; jaws with 2 or 3 teeth each. 



C. deflexus (PL 34. fig. 12, dorsal view; 

 13, ventral view; 14, teeth). Carapace ovate, 

 compressed, its posterior points long and 

 directed do\ATiwards ; terminal points of foot 

 (toes, E.) shorter than the foot itself; length 

 of carapace 1-240". Aquatic. 



C. caudatus. Carapace ovate, compressed, 

 posterior points of carapace distinct, points 

 of foot longer than the foot itself; aquatic 

 and marine; length 1-240". 



C.I uncinatus and bicuspidatus are doubt- 

 ful species. 



BiBL. Ehr. Infus. 475. 



COMPRESSOR. Introduction, p.xx. 



CONCEPTACLE.— A form of fructifica- 

 tion in the Floride^e and Fucoide^. 

 Also apphed to the fructification of some 

 Fungi. 



CONCRETIONSandCALCULL— These 

 terms are rather indefinite. A hard body 

 of considerable comparative size, formed 

 within an animal organism, would be called 

 a calculus; whilst a body of considerable 

 comparative size in which hardness w^as not 

 a marked feature, or a hard body of small or 

 microscopic dimensions, would be called a 

 concretion. Under the latter term, the no- 

 tion of a compound structm-e is usually 

 implied. Calculi generally consist of various 

 organic and inorganic substances entering 

 into the composition of the secretions of the 

 body, which are precipitated from various 

 causes. Those found in the intestinal canal 

 are mostly composed of undigested vegetable 

 tissues derived from the food. Most, if not 

 all, calculi and concretions are mixed with 

 animal matter (proteine-compounds) derived 

 from the mucous cavities in which they are 

 contained, or simultaneoush' precipitated, 

 with their characteristic components, from 

 the secretions in the midst of which the}' are 

 formed. Hence when the proper calculous 

 matter is dissolved by a reagent which exerts 

 little or no action upon the animal matter, a 

 mass is left which exhibits the form of the 

 original body. 



Calculi and concretions enlarge by the 

 deposition of new matter upon their outer 

 surface ; and as this deposition is not uni- 

 form and uninterrupted, either in regard to 



