700 MR FRANK J. COLE 



labial, and would thus, on P. Furbringer's view, constitute still another head of the 

 copulo-tentaculo-coronarius. 



In front of the origin the muscle gradually tapers down, passes upwards and 

 forwards closely opposed to the dorso-posterior surface of the lateral labial cartilage, 

 and is inserted into the same surface of this cartilage immediately behind the internal 

 process. It is difficult to assign any function to this insignificant muscle, except that 

 it may assist in manipulating the first tentacle, seeing that its posterior end is fixed. 



14. M. copulo-ethmoidalis. (Figs. 3, 9, 10, 11, c.e., c. e'., c.e".). 



J. Muller, Herdbzieher der knochernen Schnautzenstiitze (p. 259). 



A stout, powerful muscle arising by two heads — an antero- external (c. c.) and a 

 postero-internal (c. e'.). The former head was not distinguished by J. Muller or 

 P. Furbringer, but I find it invariably present both in dissections and sections. 



The external head arises from the superficial fascia at the region of the antero- 

 dorsal border, and also from that of the antero-internal margin, of the copulo-palatinus. 

 It appears on the surface immediately in front of the latter muscle and of the anterior 

 border of the obliquus muscle, and below the cornual cartilage. Its fibres pass upwards, 

 forwards, and inwards in an arch underneath the cornual and lateral labial cartilages, 

 and soon unite with the other head to form the antero-ventral portion of the insertion. 



The internal head arises medianly to the preceding, mostly from the external 

 surface of the bulb of soft pseudo-cartilage at the anterior end of the external bar of the 

 anterior segment of the basal plate, but some of the ventro- external fibres arise from 

 the dorso-external surface of the hard cartilage of the anterior extremity of the external 

 bar itself. The fibres of the internal head pursue a similar course to those of the 

 external head, and form the postero-dorsal portion of the insertion. The lateral labial 

 cartilage lies in a depression on the dorsal surface of this head. 



As the copulo-ethmoidalis passes forwards it becomes greatly compressed from side 

 to side, and bent in the form of a vertical crescent with the concavity directed 

 externally. It appears on the surface of the roof of the mouth (covered, of course, by 

 the mucosa), as shown in fig. 10, c. e" '., and is inserted by about the central portion of 

 the inner or convex surface into the entire extent of the lateral surface of the subnasal 

 bar, from about the posterior extremity of the anterior soft cartilage portion to the 

 anterior end of the insertion into the same of the palato-ethmoidalis profundus. All 

 the fibres are, however, not inserted into the subnasal bar, since there are some 

 inserted into the fascia immediately above and below this cartilage, and these were in 

 fact, in the sections, continued forwards somewhat in front of the fibres inserted into the 

 the bar. 



The function of the copulo-ethmoidalis is to compress the mouth cavity vertically 



