PSYCHE. 



393 



seen and — important facts — the third 

 pair belongs to the intercalary segment 

 and the fiftli to the superlingual somite. 

 The lingiui has no ganglia. Later, the 

 first three pairs unite to form the supra- 

 and the remaining four, the suboeso- 

 phageal ganglion. 



More conclusive proof that the inter- 

 calary and superlingual appendages 

 represent jirimitive segments, of which 

 there are seven, could hardly be 

 expected. 



In Campodea (Uzel '9S) and Ephe- 

 mera (Heymons '96) the hypopharynx 

 originates as three independent anlagen 

 and several authors have held it to 

 represent a somite upon anatomical 

 grounds. The hypopharynx of highly 

 specialized insects, howevei", I rind to 

 be homologous with simply the lingua 

 of Collembola and ThySMUura, although 

 the superlinguae arc represented in the 

 more generalized Pterygota but have 

 usually been overlooked or disregarded. 



Among Aptervgota the lingua and 

 superlinguae do not unite, although 

 their three cavities become basally con- 

 fluent with the general body cavity. 

 In Orthoptera and Ephemeridae, how- 

 ever, the superlinguae are firmly united 

 with the lingua. Although often con- 

 spicuous in the latter group (Vayssifire 

 '82), the superlinguae are less so in 

 Orthoptera but I have found them as 

 distinct lobes in all families of the 

 order. The chitinous lingual stalks, 

 important in Collembola and Cam- 

 podea, become reduced and function- 

 less in Machilis and Lepisma but occur 

 as rudiments even in Orthoptera, 



including Hemimerus (Hansen '94). 

 Miall and Denny ('86) have figured 

 them for Periplaneta and I have found 

 them clearly in Melanoplus femoratus. 

 Tliere are striking and detailed agree- 

 ments between the anterior somites of 

 insects and decapod Crustacea. Vial- 

 lanes ('87) and Hansen ('93) have 

 emphasized the fact from their respec- 

 tive standpoints of embryology and 

 comparative anatoni}'. My own results, 

 confirming and supplementing their 

 views, may partially be expressed in 

 tabular form. Between such divergent 

 groups, of course, homologies indicate 

 nothing more than a parallelism in 

 development. 



Ecjl-IVALENT PAIRED OrGAXS. 



So)nit€ ilexa/'odiz Crustacea 



1 Compound eyes Compound eyes 



2 Antenn.ie Antennules 



3 Intercalary appendages Antennae 



4 Mandibles Jlandibles 



5 Superlinguae First Maxillae 



First Maxillae Second Maxillae 



7 Labium First Maxillipedes 



Works Cited. 



Claypole, A. M. '98. The Embryology 

 and Oogenesis of Anurida maritima (Gudr.). 

 Jour, raorph., vol. 14. 



Hansen, 11. J. '93. Zur Morpliologie der 

 Gliedinassen unci Mundtheile bei Crustaceen 

 und Insecten. Zool. anz. jhg. 16. 



Hansen, H.J. '94. On the Structure and 

 Habits of Hemimerus talpoides Walk. En- 

 tom. tidsk. arg. 15. 



Heymons, R. '95. Die Segmentirung des 

 Insectenkorpers. Abh. preuss. akad. wiss. 

 Berlin. 



Hejinons, R. '96. Grundziige der Ent- 

 wickelung und des Korperbaues von Odona- 

 ten und Ephemeriden. Abh. preuss. akad- 

 wiss. Berlin. 



