130 W. C. ALLEE. 



care should be taken in clearing up the area just anterior to the 

 f orebrain. Otherwise the delicate olfactory nerves and the nerves 

 to the eyes will be entirely destroyed. Similar care should be 

 taken to preserve the long and delicate nerves which pass from 

 the posterior border of the main nerve ring to the chilaria and 

 operculum. 



The nerves arise from the central nervous system in groups of 

 two; one dorsal, called the haemal, and one ventral, the neural 

 From the nerve ring, eight pairs originate; six large anterior ones 

 and two smaller posterior ones. In addition a median and two 

 lateral olfactory nerves ; a median and two lateral eye nerves, arise 

 from the front of the ring. Great care must be used in finding 

 them. The ventral nerve cord has five ganglia with pairs of 

 haemal and neural nerves from each. The last three sets of 

 nerves join the posterior end of the cord. Find as many of the 

 nerves as you can. An instructor will demonstrate and complete 

 the dissection where possible. 



6. Study the arrangement of the coxal glands, the brick-red 

 tubes which lie lateral to the nerve ring. This is the excretory 

 system. 



In the absence of an instructor the following papers will be of 

 assistance : 



Lankester, E. Ray. Is Limulus an Arachnid? Quart. Journ. Micr. Sci., 21, 



N. S., iSSi. 



Placed Limulus with the Arachnida. 



Patten and Redenbaugh. Studies on Limulus, I. The Endocranium of Limn- 

 lus, Apits and Mygale. Jour. Morph., 16, 1899. Studies on Limulns, II. 

 The Nervous System of Limulus with Observations upon the General 

 Anatomy. Jour. Morph., 16, 1899. 



Morphological account ; good figures ; direct aid in dissection. 

 Patten and Hazen. Development of the Coxal Glands, Branchial Cartilage and 



Genital Ducts of Limulus polyphemns. Jour. Morph., 16, 1900. 

 Patten, Wm. The Evolution of Vertebrates and their Kin. Blakiston, Phila., 



1912. 

 Complete bibliography. 



