802:, 



COMPENDIUM OF GENERIC DISTINCTIONS. 



CLASS-ANNELIDA. 



'Elongated No jointed feet, often with bristles or 

 tubercles for progression Respiration by gills, sacs, 

 or skin. 



Order. SETIGERA Body with bristles or bristle- 

 bearing rudiments of feet. 



Family. AMPHITRITJE. Head not distinct. Eyes none. 

 Body mostly in a tube. 



Genus. SABELLA. Mouth transverse, across gills. Gills 

 two, feathery ; funnel comb-shaped, spiral, and large. Cylin- 

 drical stopper. Front tubercles with hooks and bristles. 

 Tube gelatinous, covered with sand. 



Genus. SERPDLA. Gills two, combed, fan-shaped. Tube 

 not erect, calcareous, twisted. 



Genus. TEREBELLA. Upper lip surrounded by long 

 tentacles. Tubercles with double row of hooks. Gills 

 branching. Tube composed of sand and shells. 



Family. NEREID/E. Body long, slender ; head distinct, 

 with tentacles and eyes. Gills like lobes of feet. Tubercles 

 throughout all body. Proboscis large, often with two horny 

 jaws. No tube. 



Genus. PHYLLODOCE. Head small. Eyes two ; tentacles 

 four or five, the last very minute. Jaws none ; proboscis 

 thick and tentacled. Two bristles at end of body. 



Genus. NEREIS. Eyes four ; tentacles four, short. Jaws 

 powerful ; proboscis thick and cylindrical. 



Family. ETTNICE.S3. Body long, many segments. Pro- 

 Uoscis with seven to nine horny jaws. 



Genus. EUNICE. Head distinct, tentacles five. Comb- 

 like gills in front of body. Jaws seven. 



Family. ARICI&. Head scarcely distinct. Body small 

 at.each e'hd. Proboscis short ; jaws none. 



Genus. CiRBHATDLCa. Body long, round, a few bristles 

 on back and belly ; cirrhi long. Gills like very long cirrhi 

 in front of body. 



Family. ARENICOLIDJE. Gills tufted in middle of 

 body. Double row of bristles along sides. Head not distinct ; 

 eyes and jaws wanting. 



Genus. ARENICOLA. Segments divided by folds, thick 

 in front, smaller behind ; no bristles behind last pair of gills. 

 Mouth with retractile proboscis. 



Family. CILETOPTERID.. Front and hinder tubercles 

 with a bundle of bristles, but without hooks. Those of 

 middle with a large membranous appendage. 



Genus. CHAITOPTERUS. Long, enclosed in leathery tube. 



Family. APHRODITID^B. Body oval. Head with 

 tentacles ; eyes two or four. Flaps distinct, with spine and 

 bristles. 



Genus. APHRODITE. Head hidden under scales or 

 oristles. Eyes two; tentacles three. Jaws very small or 

 wanting. Body rather flattened. 



Family. LTJMBRICID.ffi. No gills. Body with bristles, 

 but no tubercles. 



Genus. LUMBRICUS. Nearly cylindric, narrow at both 

 ends, blunt behind. Mouth nearly at tip. Bristles not re- 

 tractile. Saddle composed of swollen rings hi front of body. 



Order. SUCTORIA. Body without bristles, with a 

 sucking disc at one or both ends. No external gills. 



Genus. HIRUDO. Body oblong, rather flat. Jaws three, 

 with double row of crowded teeth. Eyes ten. 



Genus. H^MOPIS. Double row of few teeth. Eyes ten. 



Genus. BRANCHIOBDELLA. Body with large and few 

 rings. Eyes none. Jaws two, horny. 



Genus. A LBIONE. Body narrowed in front, rings 

 numerous. Mouth small, narrowed at bottom of front 

 sucker. Hinder sucker at end of body. 



Genus. NEMERTES. Several eyes ; two pics at side of 

 head, surrounded by cilia. 



Sub-class. ENTOZOA. Parasitical. Mostly 

 elongated. No special organs of breathing. Found inside 

 living animals. 



Order. STEREIiMINTHA Intestine absent in some, 

 vascular in others. 



Family. CESTOIDE.S!. Body long, flattened, soft. No 

 mouth, head mostly with sucking discs. 



Genus. T^NIA. Body long, jointed. Head with four 

 sucking discs, mostly with beak surrounded with hooklets. 

 . Genus. BOTHRIOCEPHALUS. Head swollen, with two or 

 four opposite furrows. 



Genus. ECHINOOOCCUS Vesicles single or enclosed in 

 cryst. Many minute Entozoa in interior surface. 



Order. TURBELLARIA. Body cylindrical or flat- 

 tened, mostly not jointed, or wrinkled throughout, covered 

 with cilia. 



Family. NEMERTID.S!. Body very long, very con- 

 tractile, indistinctly rintred* 



Order. CJELELMINTHA Intestine in a distinct 

 cavity. 



Tribe. HEM A TOIDEA.Body round, elastic. 



Family. STRONGYLIDID.E. Mouth at or nearly at 

 end of body, not surrounded with retractile hooks. Body 

 round, long, and elastic. 



Genus. STRONGYLUS. Body very long, sharp in front 

 Mouth round or triangular. 



Genus. ASCARIS. Body sharp at both ends. Head three- 

 valved. 



Genus. TRICOCEPHALUS. Body thread-like in front, sud 

 denly thickening behind. 



Genus. FILAKIA. Body very long, thread-like, nearlj 

 equal throughout. Mouth rounded. 



CLASS.-ECHINODERMATA. 



Radiate, skin more or less leathery, having variously- 

 shaped chalky pieces imbedded. 



Sub-class. DITREEMATA. Digestive canal dis- 

 tinct, with two openings ; outline of body entire. 



Order. HOLATHUROIDEA Shell none ; no chalky 

 pieces. Body cylindrical, moving by alternate extension 

 and contraction. 



Family. THALASSEMAD.ffi. Proboscis with long, fleshy 

 appendage. No tentacles. Vent at end of body. 



Genus. THALASSKMA. Body cylindrical, rounded, and 

 smooth behind. Proboscis short. 



Family. PRIAPULIDJE. Proboscis retractile. Tentacles 

 none, vents at end of long tail. 



Genus. PRIAPULUS. Bod- blunt behind. Tail branched 

 and pointed. 



Family. SIPTTNCTJLID^ 7 Proboscis retractile, tentacled 

 at tip. Vent at base. 



Genus. SYRINX. Proboscis shorter than body. Tentacles 

 fingered. 



Genus. SIPUNCULUS. Proboscis long as body. Tentacles 

 not fingered. 



Order. HOLOTHUROIDEA. Shell none. Skin with 

 chalky netted pieces ; a ring of same substance round 

 gullet. Locomotion mostly by suckers. 



Family. PSOLIDJE. Suckers three rows on oblong disc ; 

 two rows rudimentary. 



Genus. PSOLUS. Body iiregular, slug-like. Tentacles 

 ten. 



Family. PENTACTAD.ffi. Suckers in five regular rows. 

 Body irregular. 



Genus. PENTACTA ( includes CUCUMARIA ). Suckers 

 alternate in each row, close. Tooth-plates nearly square. 

 Tentacles ten. 



Genus. PsotiNUS. Body curved. Suckers distinct from 

 each other. Under -suckers bent. Teeth short. Tentacles ten 



