NERVOUS SYSTEM IN PELECYPODA 



207 



osphradia, and ^■iscera generally, forming a special genital gang- 

 lion in connection with the reproductive organs. Tlic principal 

 ganglia of tlie l)iljran('luata are still more concentrated, even 

 the visceral loop being possibly nnited with the rest in forming 

 an iinbroken mass in wliich scarcely any trace of commissures 



Fi(i. 106. — Nervous system of Cardium edide L.: a.m, iinterior ;idductor juiiscle ; br, 

 branchiae; hr.n, brancliial nerve; eg, eg, cerebral ganglia; c.^.t, cerebro-pedal 

 comiuissure ; c.v.c', cerebro-visceral commissure ; c.v.c, cerebro-visceral commissure 

 of mantle ; I.j), labial ^jalps ; vi, mouth ; p.g, pedal ganglion ; i'-"', posterior adductor 

 muscle ; r.y, visceral ganglion. (After Drost, x o. ) 



can l)e detected. Tlie pedal ganglion becomes separated into 

 two portions, one of which innervates the arms, tlie otlior the 

 funnel. Two ])eculiar ganglia (the stellate ganglia) supply a 

 Handler of brauchim'' nerves to the mantle. 



E. L, Bouvier, Systume nerveux, morpliologie generale et classiticaliou des 

 Gastt'ropodes prosobraiiclies : Ann. Sc. Nat. Zoo]. (7'' iii. 1887, 

 pp. 1-510. 

 J. Brock, Zur Neurologie dcr I'rosoljranchier : Zeit. -wiss. Zool. xlviii. 



1889, pp. 67-83. 

 0. Biitschli, Bemerkungon ul)er die \valii'8cliL-inliclie Herk-itunij, di i- Asyni- 



nietiie der (lasteropoda, etc. : Morpli. Jalirb. xii. 188C, pp. 202-222. 

 B. Haller, Zur Kenntniss der Muriciden. I. Anatoiuie des Xervensystenis : 

 Denksch. Matli. Nat. KL Ak. Wien, xlv. 1882, pp. sV-lOG. 

 „ Untersiicliungeu iiber marine Rhipidoglossen. II. Textur des 



Centmhiervensystems und seiner Hiillen : !Morpli. Jaliib. 

 xi. 1885, ])]\ 319-436. 



