PACIFIC COAST OLIGOCH MTA. 125 
respective species either diffuse or micronephridia arranged in three, four or more 
rows on either side, some species showing several gradations. Spermatheca two pairs, 
contracted at center with one or more small diverticula, Penial sete nearly always 
present. Generally small, tropical worms. 
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DEFINITIONS OF AMERICAN SPECIES OF BENHAMIA. 
Benhamia nana n. sp. 
Derinition. Size 
pigmented. First dorsal pore between iii/iv. Prostomium very swollen and overlapping. 
Length 20 to 30 mm.; number of somites 110; skin strongly 
Clitellum complete in central somites. Penial setie, the largest with 12 or more bristles. 
Common sete, distance between the dorsal couples about equal to that between the ventral 
couples. Oviducts, two pores, open in front of 1 and 2. Prostate pores not on papille. 
Pharynx situated very far forward. Gizzards in viii and ix. Caleiferous diverticula, 
two pairs in xv and xvi. Sperm-sacs in x and xi. Spermducts thicker at the base in 
voi, wou and «xvi. Nephridia in three rows on either side, the posterior with calomic 
mantle. Spermatheca, basal part with one diverticulum, apical part warty and irreg- 
ular.  Typhlosole large, begins in xviii. Color brownish red. Habitat, San Blas, 
Meico, at sea level. 
Benhamia mexicana Rosa. 
Derrrinition. Length 30 mm.; number of somites 120. Skin not pigmented. 
First dorsal pore between iii/iv. Prostomium divides the first somite completely. Cli- 
tellum complete in xiii to wxi. Penial sete not ornamented (?); common sete, 3 and 4 
further apart than Land 2. Oviducts, two separate pores in front of 1and 2, on small 
papille. Gizzards in vii and ix. Calciferous gland 3 pairs in xv, avi and xvii. Ne- 
phridia in 3 rows on either side. Spermatheca with a single short diverticulum. Alco- 
holic specimen colorless. Habitat, Durango, Mexico, at 2500 meters altitude. 
Benhamia Bolavi Michaelsen. 
Derinition. Length 40 to GO mm.; number of somites 97. First dorsal pore 
between v/a. Clitellum incomplete in all somites, xiii to xx. Penial sete, the largest 
with five to eight notches, the smaller spoonlike and slightly forked; common sete couples 
equidistant. Oviducts open in one single pore on a median papilla in wiv. Gizzard two 
mv. Caleiferous gland three pairs in xv, xvi and xvii. Sperm-sacs one pair in wi. 
Nephridia in three rows on either side. Spermatheca, the basal part with a single small 
diverticulum. Saculated intestine begins in xxi. Color dingy flesh. Habitat, Venezuela 
(and Hamburg). 
Benhamia palmicola n. subsp. 
Derinition. Length 50 to 60 mm.; number of somites 90. Skin not pigmented. 
First dorsal pore between iv/v. Olitellum incomplete in all somites. Penial sete, largest 
with four notches, the smaller one spoonlike and forked; common sete about equal dis- 
tance between the dorsal and ventral as between the ventral couples. Oviducts open in one 
single pore on a median papilla. Gizzards both in viii. Caleiferous gland 3 pairs in 
