ANNULOSA. 43 



(Leydig, Ueber den Bau und die systematische Stellung der Rdderthiere, 

 Zeitschr. fur Wiss. Zool., 1851 and 1854 ; Gosse, On the Structure, Func- 

 tions, and Homologies of the Manducatory Organs of the Class Rotifera, Phil. 

 Trans., 1856 ; Grenacher, Beobachtungen iiber Raderthiere, Zeitschr. fur 

 Wiss. Zool., 1869 ; Huxley, Lacinularia socialis, Trans. Micros. Soc., 1853.) 



DIVISION II. ANAETHEOPODA. 



CLASS I. GEPHYREA (Spoon- worms). 

 ORDEU I. GEPHYEEA IXEKMIA. 



Fam. a. Priapulidse. Priapulus. 



Fam. b. Sipunculidse. Sipunculus (fig. 38), Phascolo- 



soma. 

 OKDER II. GEPHYREA ARMATA. 



Fam. a. Echiuridse. Echiurus, Tkalassema. 

 Fam. b. Bonelliadse. Bonellia. 



Fig. 38. Gephyrea. Sipunculus Indicus, of tlic natural size. (After Keferstcin.) 



The genus Sternaspis, which has been often placed among the Gephyrea, 

 is now regarded as an Annelide. 



The genus Phoronis, on the other hand, usually placed among the 

 Tubicolar Annelides, is sometimes looked upon as the type of a special 

 section of Gephyrea. 



(Keferstein, Beitriige zur anatorn.ischen und systematischen Kenntniss der 

 Sipunculiden, Zeitschr. fiir Wiss. Zool., 1865 and 1867 ; Semper, Mitthei- 

 lungen iiber Sipunculiden, Zeitschr. fiir Wiss. Zool., 1864.) 



