![](/drem/stage19/labels2/S81L.gif)
![alar plate of myelencephalon, alar plate(s), cerebral aqueduct (mesocoele), osteogenic layer, rhombencoel (fourth ventricle), roof of rhombencoel (fourth ventricle), roof plate, roof plate of mesencephalon, root of trochlear nerve (CN IV), subarachnoid space](/drem/stage19/Z0/S81N.jpg)
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Carnegie Embryo #9325 | Location: 3-2-1
Keywords: alar plate of myelencephalon, alar plate(s), cerebral aqueduct (mesocoele), osteogenic layer, rhombencoel (fourth ventricle), roof of rhombencoel (fourth ventricle), roof plate, roof plate of mesencephalon, root of trochlear nerve (CN IV), subarachnoid space
Source: The Virtual Human Embryo.