IX 



MOLLUSCA 



303 



succeed, iu keeping his larvae alive for more than a week. Kecently, 

 however, the larvae of Patella vuljata have been reared through their 



met 



m. 



ttr 



Flo. 238. Frontal section of a veliger larva of Patella coernlea in order to show the 

 mesodennie hands. (After Patten.) 



a;), apical plate; in.li, mesodermic band ; m.ch, mesenchyme cells budded off from the front ends 

 of the mesodermic bunds ; at, stomach ; t.tr, telotroch ; V, velum. 



FIG. 239. Frontal section through the pretroehal region of an old veliger larva of 



Patella coerulea. (After Patten.) 

 Lrtteis as in i>re\ ions figure, c.ij, rudiment of cerebral f?anxlioii. 



entire metamorphosis, until they assume tlie adult form. This result 

 has been accomplished in Plymouth, using Nitschia as food. The field 

 is therefore open for a renewal and revision of Patten's work. 



