1894.] Schulze’s System of Descriptive Terms. 379 
aboran regions and extend ectad, spreading out during its 
progress into a support suitable to anchor the body of the 
sponge in the mud below. The spines of Xiphacantha would 
be ento-ectal (extending from the centrum to the distans” 
surface and then ectad) having their origin in a central mass, 
possessing radiating spines on the distan surface and passing 
ectad of these to a variable distance. y 
Professor Gage objects to this in the following words “ It 
seems to me the suggestions with reference to ectal, etc., are 
not happy. Proximal and distal seem to me to express near- 
ness and remoteness of appendages to tbe part from which 
they arise. That may be reference toa limb or the trunk 
taken as the origin. For example, the arms and legs are 
appendages of the trunk, their distal ends being the hands 
and feet and the attached ends the proximal. So just as prop- 
erly, in accordance with the established use of proximal and 
distal, the attached end of the hair is its proximal end while 
the free end is distal. This is true whether the hair is on the 
trunk or an appendage. I think the use originally made of 
ectal and ental by yourself (Wilder) the best one, the funda- 
mental idea is in the compounds Ectoderm and Entoderm.” 
These criticisms coming from such a source and appealing 
to the derivation of the words are consistent with the Bar- 
clayan system and would be very convincing but for one 
thought that makes me hesitate to abandon this suggestion 
until I can learn more from experience. If the terms ectal 
and ental are to be applied to parts without reference to their 
origin, but simply because they are external and internal, it is 
obvious that they cannot be restricted any more than the 
words, outside and inside. If one is describing a spine or 
appendage of any sort the surface is ectal, the inner part 
ental, but if one is describing the body with reference to its 
appendages, the spines are ectal or they may have parts within 
the body and these are ental. The limbs of the Vertebrata 
and Crustacea may be considered either with reference to the 
surface of the body or to the skeleton, but the stalk of a hya- 
lonema and the spine of Radiolarian may originate from the 
centrum itself. 
7A better word here is peripheran. 
