122 MICROSCOPICAL STUDIES. 



Alcyonidium, and Bowcrbankia (marine) and Paludicella (fresh- 

 water). 



Sub-Order c. Cheilostomata. Zooecial orifaces furnished with a 

 movable thickened lip or operculum, or with a sphincter muscle ; 

 vibracula and for avicularia usually present, e.g., Actca, Buyula, 

 Flustra, Scrupocellaria, Lcpralia.* 



STUDY XXV. THE SAPPHIRINIDJS. 



The Sapphirinidae are Copepoda of large size found in warm seas. 

 The males are free-swimming and pelagic, captured usually in the tow- 

 net, whereas the females are seldom taken free, as they pass their life 

 as commensals or messmates in the branchial cavities of such pelagic 

 Ascidians as Salpa. 



The females differ considerably from the males in form, as is usual 

 with species where the sexes have divergent habits. In this article we 

 shall confine attention to the males. 



Male individuals of this family are all of comparatively large size, 

 the body is dorso-ventrally compressed, and these characteristics in 

 conjunction with the perfect transparency of the chitinous covering 

 makes the Sapphirinida a splendid type-group wherein to study with 

 ease the structure of all the internal organs. 



The prevailing body-form of the Copepoda is pear-shaped, and the 

 common Cyclops, abundant in fresh-water ponds, is a good representa- 

 tive. In the Sapphirinida, as already mentioned, the body is flattened ; 

 in contour it is oval, showing a large cephalic shield, five thoracic 

 segments, and an equal number of abdominal segments terminating in 

 two leaf -like caudal lamellae. Only four of the thoracic segments are 

 readily distinguishable, the fifth being rudimentary (PI. X., Fig. 1, th.). 

 The first abdominal is marked by the external openings of the sexual 

 organs being here placed. 



The appendages are of the normal Copepod type, save in the form 

 of the posterior antennae (p>a.) and of the appendages around the 

 mouth (maxillae), which terminate in hook -like claws well adapted 

 both for clinging to the host should the Copepod be sojourning with 

 one, and for grasping the female during accouplement. A swimming 

 foot of Sapphirina Clausi of typical Copepod form is shown at Fig. X., 

 consisting of an inner and an outer branch (endo- and exo-podite) of 



* The marine Bryozoa live well in confinement and several kinds (Pediccllina, 

 Alcyonidium^ Flustrella, Amathia, &c.) can be supplied living from the Jersey 

 Biological Station. It is advisable to give, if possible, a couple of days' notice. Full 

 particulars supplied on application to the Director. 



