REPORT ON THE ALCYONARIA. Ivii 



23. Muricea, Auct. emend. Verrill (as subgen. ).. Trans. Connect. Acad., vol. i. p. 450, 

 1869. 



The colony is branched, with a thick coencnchj^ma and terminally bilobed polyp 

 calyces markedly projecting. In the polyps when retracted the dorsal half of the calyx 

 projects as a lip. The tentacular operculum is drawn into the calyx. The spicules are 

 either warty spicules, which are usually short and thick, or they sometimes approximate 

 to the club-shaped form. Besides these, long spiny spicules usually occur in the deeper 

 layers. 



Family IX. P L E X A u R i D .E. 



Plexauridx, Gray, Ann. and Mag. Nat. Hist., ser. 3, vol. iv. p. 444, 1859. 

 Euniceiilee, KciUiker, Icones bibtiologicEe, pt. ii. p. 137, 18.t9. 

 Plexauridx, Verrill, Trans. Connect. Acad., vol. i. p. 413, 18G9. 

 Plexmmdx, Klunzinger, Korallthiere des rothen Jleere.^, pt. i. p. 51, 1877. 



The polyp colony is usually branched and upright. The axis is horny, or horny and 

 calcareous, especially at the base. The ccenenchyma is thick. The polyps occur over 

 the whole circumference of the ccenenchyma. The anterior tentacular and oesophageal 

 portions of the polyps are retractile into a calyx region, forming wart -like protuberances, 

 or they are completely retractile into the ccenenchyma. Thus, in many instances the 

 apertures of the polyps appear as openings or simple pores in the ccenenchyma. The 

 canalicular system consists of small reticulate canals, radiating from the polyp cavities, 

 and opening finally into the longitudinal canals, which latter are arranged .symmetricall)' 

 around the axis. The spicules arc usually large, of variable form ; the cortical layer 

 mostly consists of a layer of clubs, beneath which .spindle-shaped spicules are found. 

 The tentacles of the polyps are at their bases provided with spindle-shaped spicules. 



Verrill's ^ diagnosis of this family is here reproduced ; he has most tersely summed up 

 the characteristics of the group. The genus Eunieella was first referred by Verrill to 

 the Gorgonidse, but w^as afterwards - rightly placed in this family. A divergent type is, 

 however, represented by Eunieella albicans, Verrill, in which the flat axis recalls the 

 structure of many Gorgonidae. 



The Plexauridse are most nearly related to the Muriceidse, Eimicea is closely related 

 to Muricea, while on the other hand Eunieella leads on to the Gorgonidse. 



1. Eunicea, Lamouroux. 



2. Plexaura, Lamouroux. 

 3 Plexaiiroides, n. gen. 

 4. Plexaurella, Kolliker. 



5. Pseiidoplcxaura, n. gen. 



6. Euplexaura, VerriU. 



7. Psammogorgia, Verrill. 



8. Eunieella, Verrill. 



9. PlaUjgorgia, Studer. 



1 Notes ou Radiata, Tram. Connect. Acad., vol. i. p. 413. - Amcr. Journ. Sci. and Arts., vol. xlviii., 1869. 



