SALIVARY GLANDS OF LOWER PRIMATES 77 



along its medial boundary the submaxillary duct and its occasional 

 associate, the duct of the secondary submaxillary gland; further 

 laterad, as an inconstant intermediate component of the entire inter- 

 mandibular salivary complex, the greater subhngual (Barthohnian) 

 gland and duct, with either an independent parafrenular orifice, or 

 joined to the terminal of the greater submaxillary duct ; lastly, on the 

 lateral border of the entire area, and extending thence in some forms 

 dorsocaudad into the arcus palatinus and the soft palate, the group 

 of the smaller subhngual (Ri\-iman, or, in Chievitz's sense, "alveololin- 

 gual") glands with numerous separate orifices along the lateral hne 

 of the oral floor. 



Logically, perhaps, the collection of lateral separate glands could 

 be defined, within the Hmits of the alveolingual area, as the "alveolar" 

 group, or, more correctly, as the "median alveolar" group, in contra- 

 distinction both to the "lateral alveolar," or so-called "inferior molar" 

 glands of the inferior alvaobuccal sulcus, and to the two remaining 

 components of the entire alveolingual field above mentioned. In this 

 case the constant median element would, with its occasional further 

 accessory and secondary derivatives, be genetically referred to the 

 median or lingual sulcus, as the generalized submaxillary hne, while 

 the inconstant greater sublingual or Barthohnian gland and duct 

 would appear as an additional development, intermediate between the 

 lateral and medial boundaries of the entire field. 



In view, however, of the adoption by the B.N. A. of the term "Duc- 

 tus sublinguales minores" for the Rivinian series of the lateral glandular 

 orifices, it seems wise to extend the scope of this term to include the 

 glands of these ducts and to define them consequently as the Cdaiidula- 

 sublinguales minorcs or Lesser sublingual glands. This terminology 

 is therefore used in the following, as defining the lateral .group of 

 individual isolated glands of the alveohngual area, frequently described 

 as the Rivinian series. 



(b) Isthmian glands. — A group of discrete separate glands with 

 individual duct orifices which lie beneath the oral mucosa as the latter 

 turns cephalodorsad into the palatine arch. 



In many cases these glands appear in the lower primates in the 

 direct hne of the caudal prolongation of the lesser subhngual series, only 

 separated from the latter by the Ungual nerve. It often appears as if 



