354 



ON A COLLECTION OF ECHIURIDS, WITH AN ATTEMPT TO 



ANALYTICAL KEY TO THE SPECIES OF THALASSEMIA. 



It has been found impossible to incorporate Verrill's species Th. viridis in the 

 following key, as we have no knowledge of the condition of the longitudinal muscles 

 or of the number of the nephridia. 



i proboscis about as long as body 77.. diaphanes, Sluiter. 



1 pair of I proboscis small Th. faex, Selenka. 



nephridia 1 proboscis not very wide, trilobed at tip Th. gigas, Max Muller. 



V proboscis wide and indented at tip, bilobed ... 77*. lankesteri, Herdman. 



Longitudinal 

 muscles in a , 

 continuous 

 sheath 



2 pairs of I Th. neptuni, Gaertner. 



nephridia ( Th. temoni, Fischer. 



3 pairs of | with proboscis Th. moebii, Greef. 



nephridia I with no proboscis(?) Th. vegrande, Lampert. 



/ 1 pair of 1 

 nephridia / 



Longitudinal 

 muscles J 



divided into 

 bundles 



2 pairs of 

 nephridia 



3 pairs of 

 nephridia 



1 



Th. hupferi, Fischer. 



17-19 bundles of longitudinal muscles Th. baronii, Greef. 



8-10 

 7 8 

 8 

 13 



16-18 

 14 



17-18 

 15-16 

 13 

 V 15-16 



Th. exilii, Fr. Muller. 

 Th. formosttlum, Lampert. 

 77-. mellita, Conn. 

 Th. /•■ 'lucidum, Fischer. 



■ . Lampert. 

 Th. erythrogramnum, 



Max Muller. 

 Th. k-okotoniense, Fischer. 

 Th. leptodermon, P'ischer. 

 Th. s . Lampert. 



Th. stuhlmanni, Fischer. 



