NEMATODE PARASITES OF BIRDS 163 



KEY TO FAMILIES OF SPIKUttOIDEA 



1. Mouth with 2 large trilobed lips with a longitudinal ridge on their Inner 



surface meeting the one on the opposite sides; adults in gastric tract of 



carnivorous mammals ; larvae may occur in birds.,- Gnathostomidae, p. 863. 



Month without lips or with lips different from above; adults (except in 



Spirocerca) may occur in birds 'J. 



2. In orbital region or respiratory tract 3. 



In digestive tract 4. 



3. In respiratory tract; distinctive larval characters maintained into adult life, 



both male and female may have cluster of filiform papillae at caudal ex- 

 termity ; male without caudal alae or papillae of usual type. 



Desmidocercidae, p. 208. 

 In orbital region. Adult male and female without larval characters as in 

 above. Male with or without caudal alae and with caudal papillae »f 

 usual type, the preanal papillae being especially numerous. 



Thelaziidae, p. 311. 



4. Marked sexual dimorphism, the female robust, more or less fusiform or 



globular, the male small and slender, without caudal alae. 



Tetrameridae, p. 333. 

 Sexes not dimorphic; male with caudal alae 5. 



5. Anterior region of body with cuticular ornaments 6. 



Anterior region lacking cuticular ornaments 7. 



6. Head with 4 pinnate, posteriorly directed processes; mouth without lips or 



with 2 small papilliform lips ; bird forms found in gizzard. 



Ancyracanthidae, p. 301- 

 Cuticular ornaments of anterior region different from above; 2, 4, or G 

 triangular lips; in esophagus, proventriculus or gizzard of birds. 



Acuariidae, p. 210. 



7. Male with circumscribing caudal alae continuous anteriorly and with a group 



of 4 or 5 pairs of long pedunculated papillae in cloacal region. 



Physalopteridae, p. 295. 

 Caudal alae of male not continuous anteriorly and without above arrange- 

 ment of papillae Spiruridae, p. 163. 



Family SPIRURIDAE Oerley, 1885 



Family dmynosis. — Spiruroidea (p. 162) : Mouth with 2 or 4 ex- 

 panded lips, or without lips. Male with caudal alae and dissimilar 

 spicules. Female with vulva of variable position, but usually located 

 in the median portion of body. 



Parasitic as adults in mammals and birds, oeuerally in the diges- 

 tive tract. 



Type-geniis. — Sphwa E. Blanchard, 1849. 



KEY TO SUBFAMILIES OF SI'IROUIDAE 



1. Inadequately described species Subfamily uncertain, p. 205 



Description adequate for subfamily determination 2. 



2. Mouth without lips or disk; cervical region ornamented with cuticular 



bosses; vulva near posterior extremity Gongyloneminae, p. 203. 



Mouth with lips <>r with circular projecting disk; cervical region without 

 cuticular bosses; vulva usually remote from posterior extremity. 



Spirurinae, p. 164. 



