294 



ZOOLOGY. 



mental males are degraded, imperfect forms^ with sometimes 

 no mouth or digestive canal. The apparent design in nature 

 of their different sexual forms is to effect cross fertilization. 

 The eggs pass from the ovaries into the body-cavity, where 



Fiq;. 228.— Anatomy of Lepas fascicular is. A. c, elx pairs of legs or cirri ; /, fila. 

 nieiirary appencliiges ; m, mouth; 5, stomach; h, openings of the liver (f) into the 

 stomach, which is represented as laid open ; i, intestine ; rt, vent ; t, testis ; t\ vasa 

 deferenlia, one cut off ; p, male appendage ; 0, ovary ; e, adductor muscle connecting 

 tlie two basal valves; vs, scntal valve ; vc, carinal valve ; vi, tergal valve. Enlarged 

 twice. 



B. 1. palpus ; 2, mandibles ; 3 and 4, first and second maxillse. 



0. Nervous system, s, brain, sending the optic nerves to the nidimentai'y eye (e). 

 each optic nerve having an enlargement near the eye, i.e., the ophthalmic ganglion (0); 

 between and a are the nerves which go to the peduncle ; n, nerve sent to the ad- 

 dvcior scuioi'Uin • i¥, commissure between the supra- and infraoesophageal ganglia {yi) 

 c, c, c, c, c, c, nerves to each of the six feet. Enlarged four times.— After Kingsley. 



they are fertilized, and remain for some time. They pass 

 through a morula condition, a suppressed gastrnla or two- 

 layered state, and hatch in a form called a NmqMus^ from 

 the fact that the free-swimming larva of the Entomostraca 



