ZOOLOGY. 355 



aiy traces of it in the male; antenna^ usually riulimentary; eyes large 

 ill the male, often excessively so, occupying nearly the whole head: 

 Pleotomus, Lamproplioruft, Mierophotm^ LampyriSj and Lamprorhiza. 

 (Condensed from J. E. 21. S., vol. iii, pp. 777-770.) 



POLYZOANS. 



RELATIONS OF. THE POLYZOANS. 



The Polyzoans form a type which, in the early days of zoology, was 

 regarded as a class of the radiate animals. Subsequently Milne Ed- 

 wards and others agreed that the type w^as most closely related to the 

 Brachiopods, and subsequent investigation of the embryology of the 

 two types confirmed this view. The question afterward came up as to 

 the relationship of both these types to others. Until quite recently 

 it was disputed by no one that the Brachiopods were true mollusks, l:)ut 

 when anatomical and morphological investigations had revealed so 

 many differences they were dissociated from the typical mollusks and 

 segregated with the Tunicates under the name Molluscoidea. Later 

 Morse claimed that the two classes in question were more closely related 

 to the worms than to the mollusks. Professor Allman has recently 

 reviewed the condition of our knowledge of the endoproctal Polyzoa,* 

 and confesses that while he still supports the molhiscan relationships of 

 the type, he was nevertheless obliged to confess that there were features 

 in which it closely approximated the worms. Among the most signifi- 

 cant of these is the existence of a pair of symmetrically placed gland- 

 like organs w^hich open on the surface of the body in Loxosoma, and 

 remind one of the segmental organs of the w^orms. In 187- Professor 

 Nitzsch proposed to differentiate the Polyzoans into two groups, dis- 

 tinguished by the opening of the anal cavity in one case oirtside of the 

 tentacular crown, and in the other case within the same. The former 

 group was named Ectoprocta and included almost all the known forms. 

 The latter group was named Enrloprocta, and was at first framed spe- 

 cially for Fcdicllltna, but subsequently it was ascertained that not only 

 PediciUina but Urnatella and Loxosoma also exhibited the same char- 

 acteristic ; and Professor Busk has lately made known a curious form, 

 to which he has given the name Ascopodaria, found in the voyage of 

 the Challenger in deep water. It is the Eiidoprocta.^ according to Pro- 

 fessor Allman, that exhibit the closest connection with the vermes. 

 Loxosoma, it may be added, is a. parasite of Gephyreaus, and attaches 

 itself so firmly to the host that before Loxosoma had been described Mr. 

 A. M. Norman w^as led thereby to attribute its crown to a Gephyrean as 

 tentacular appendages of the tail of that worm. 



* Allman (G. J.)- Some recent additions to our knowledge of the structure of the 

 Marine Polyzoa. Jour. Liitn. Soc. ZooL, vol. xv, pp. 1-8. 



