20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



to develop a new terminology for the cephalic nerves of bipuncticeps, 

 the numerical designations of Fahlander (1938) are used. 



1. Nerves of the proto cerebrum. — The nerve to the cerebral gland, 

 N4, is present in bipuncticeps. This nerve emerges from the ventral 

 surface of the brain as a minute filament. It is concealed by a trachea 

 and a haemolymph vessel which are associated with the cerebral 

 gland (fig. 2, and pi. 2, fig. 2.) The cells of origin of this nerve are 

 located in the dorsal cortex of the frontal lobe. According to Scharrer 

 (1941) and Gabe (1952), these cells are neurosecretory in other 

 genera. The cytoplasm contains round granules which have a marked 

 affinity for the acid dyes; acid fuchsin stains these granules a deep 

 red (Gabe, 1952). In bipuncticeps, however, these cells show no such 

 granules when stained with picric acid and acid fuchsin. Some pink 

 granules were demonstrated in the tissue of the cerebral gland but 

 not in the neuronal cytoplasm. 



Arenophilus bipuncticeps is devoid of eyes and the Organ of 

 Tomosvary. The optic nerve (Ni) and the nerve to the Organ of 

 Tomosvary (N3) are, therefore, absent. A small sensory nerve (N2) 

 to the dorsal integument of the cephalic plate, which was described 

 by Fahlander (1938) in the Scutigeromorpha and Lithobiomorpha, 

 was not observed. A nerve, called nerf visceral pair by Saint Remy 

 (1887) and reported to be deutocerebral in Necrophloeophagus longi- 

 cornis, was not demonstrated in the present study and did not appear 

 in Fahlander's material. 



A sensory nerve enters the lateral portion of the frontal lobe and 

 will be considered tentatively as protocerebral until its homology can 

 be established. The fibers originate from the neurons peripherally 

 situated in the lateral clypeus. Two or three distinct branches merge 

 into a single nerve which enters the central neural mass (fig. 2,Na). 

 In the scutigeromorph this nerve enters the brain dorsomedially at a 

 groove dividing the protocerebrum from the deutocerebrum. In 

 lithobiomorphs and scolopendromorphs, it enters the frontal lobe 

 proximal to the optic nerves. Fahlander, nevertheless, classified Ne 

 as a deutocerebral nerve. 



2. Nerves of the deutocerebrum. — The largest cephalic nerve in 

 bipuncticeps is N7, the antennal nerve. At its base there are from 

 15 to 18 bundles of fibers separated from one another by connective 

 tissue (fig. 2). Three of these bundles may be traced to a group of 

 neurons located in the ventromedial portion of the antennal lobes 

 about 60 micra posterior to the anterior limit of the brain (pi. 2, fig. 

 2). Two of these fiber bundles are ventral in position, and one is 

 lateral (pi. i, inset). Since the distal articles of the antennae were 



