262 



THE ANATOMY OF INVERTEBRATED ANIMALS. 



vesicle ; and no trace of female organs exists. This is, there- 

 fore, an accessory, or " complemental " male. In Scalpellum 

 ornatum the individuals are males and females, two of the 

 former being lodged in cavities of the scuta of one of the 

 latter, as in the preceding species, and in S. rutilum. The 

 males have no mouth. S. roslratum has complemental males, 

 provided with alimentary organs attached to the interior of 

 the sac of the hermaphrodite, while S. Peronii and villosum 

 have still more perfect complemental males fixed in a like 

 position. In Ibla Cw/tu/r/ii, the female has a vermiform 

 male, provided with well-developed alimentary organs at- 

 tached within her sac ; but, in the only other species of this 

 genus, I. quadrivalvis, a similarly constructed, but here only 

 complemental male, is lodged in a relatively large hermaph- 

 rodite form. 



With regard to the habits of the Cirripedia, the majority 

 are merely cemented to foreign bodies. Anelasma and Tubi- 

 einella, however, partially bury themselves in the integuments 

 of the shark and whale, and thus prepare us for the com- 

 pletely boring habit of Cryptophialus Lithotrya, and Alcippe, 

 the latter of which (Fig. 69, 1, 2, 3) burrows in dead shells 

 on our own coasts. 



Proteolepas lives within the sac of Alepas cornuta, and 



Ftg. 70.— A. Naupliits-st&ze of Sacculina purpurea : cp. carapace. 



B. Cypri.i-&ta,ze of Lernceodiscusporcellance. C. Adult condition of Peltogaster paguri : 



a. anterior end of the body ; b, aperture ; c, root-like processes. (After P. 



Muller.) 



appears to be truly parasitic upon it, sucking the nutritive 

 juices from the soft prosoma of the animal which it infests. 



