Oatty Marine Laboratory, St. Andrews, 115 



one of which closely resembles a cricket-bat, the student is 

 confused, not instructed. Those familiar with the anatomy 

 of the Nemerteans would fail to recognize any resemblance to 

 the beautiful organs they misrepresent. Some recent authors 

 have apparently been so impressed with descriptions {sui 

 generis) of the mechanics of the proboscis, that they have barely 

 alluded to the digestivesystem, and omit to point out the crucial 

 point in regard to the opening of the mouth respectively in 

 the Enopla and the Anopla — one of the most striking features 

 in classification. Perhaps by-and-by a remark is made that 

 the opening of the mouth is beneath or behind the ganglia, 

 or that the ventral commissure of the ganglia lies between 

 the proboscidian sheath and the oesophagus ; but neither is a 

 complete statement for the group. While it may be inter- 

 esting to go into the suppositions that the proboscis is the 

 " hypophysis cerebri" and its sheath the " notochord," it is 

 well, if not better, to emphasize facts about which there can 

 be no dubiety. 



The figures employed to illustrate structure are perhaps 

 the most clamant feature. Mere inversion of a figure (which 

 occurs) is not so serious as some other cases, since it has 

 perhaps the correct parts somewhere. A figure copied from 

 Prof.Hubrecht is perplexing. It shows the proboscis extruded, 

 but its internal attachment is the cerebral commissures, whilst 

 the proboscidian sheath has wholly disappeared. One of the 

 same author's schematic figures does duty for the proboscis 

 in situ and is at variance with nature. The very indifi'erent 

 and, in some respects, inaccurate representation of the stylet- 

 region in its normal position in the body and in extrusion 

 may be contrasted with Hayek's figs. 558 and 559 with 

 advantage. A retrograde step to the period alluded to in the 

 opening paragraph has generally been made. One author, 

 who copies the accurate figure, does not acknowledge its 

 authorship, and, inspired by continental works, is unaware 

 that the observations quoted are those of a countryman. 



Prof. Hubrecht's diagram of the anterior end of a Nemer- 

 tean, showing the attachment of the proboscidian sheath near 

 the commissures, is less instructive than the older figure 

 shown by Hayek (fig. 556), and, besides, the reader is left to 

 infer that the position of the mouth shown is typical for all 

 Nemerteans, instead of being informed that it only stands 

 for the Anopla. For the general structure of a Nemertean 

 Prof. Moseley's Felagonemertes is used ; yet this somewhat 

 aberrant type is scarcely suited for such a purpose, even if it 

 had always been correctly copied, which it is not, for the 



