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 



Fig. 228. Anatomy of Lepas fascicularis. A. c, six pairs of legs or cirri ; /, flla. 

 mentary appendages ; m, mouth ; s, stomach ; h, openings of the liver (/) into the 

 stomach, which is represented as laid open ; i, intestine ; a, vent ; t, testis ; v, vasa 

 deferentia, one cut oft' ; p, male appendage ; o, ovary ; e, adductor muscle connecting 

 the two basal valves ; v$, scutal valve ; vc, carinal valve ; vt, tergal valve. Enlarged 

 twice. 



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



C. Nervous system, s, brain, sending the optic nerves to the rudimentary eye (), 

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

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

 ductor sculorum ce, commissure between the supra- and infraoasophageal ganglia (n) ; 

 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 gastrula or two- 

 layered state, and hatch in a form called a Nauplius, from 

 the fact that the free-swimming larva of the Entomostruca 



