PACIFIC COAST OLIGOCH^TA. 12§ 



respective species either diffuse or micronepliridia 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 setae nearly always 

 present. Generallv small, tropical worms. 



DEFINITIONS OF AMERICAN SPECIES OF BENHAMIA. 



Benhamia nana n. sp. 



Definition. Size — Length 20 to SO mm.; number of somites 110; skin strongly 

 pigmented. First dorsal pore between iii/iv. Prostomimn very swollen and overlapping. 

 Clitellum complete in central somites. Penial set'p, the largest ivith 12 or more bristles. 

 Common setxe, distance between the dorsal couples about equal to that between the ventral 

 couples. Oviducts, two pores, open in front of 1 and 2. Prostate p)ores not on papilke. 

 Pharynx situated very far forward. Gizzards in viii and ix. Calciferous diverticula,' 

 two pairs in xv and xvi. Sperm-sacs in x and xi. Spermducts thicker at the base in 

 xviii, xvii and xvi. Nephridia in three rows on either side, the posterior vnth cmlomic 

 mantle. Sj^errnatheca, basal part with one diverticuhim, apical part warty and irreg- 

 ular. Typhlosole large, begins in xviii. Color broivnish red. Habitat, San Bias, 

 Mexico, at sea level. 



Benhamia mexicana Rosa. 



Definition. Length ,W mm.; number of somites 120. Skin not pigmented. 

 First dorsal pore betimen iii/iv. Prostomium divides the first somite completely. Cli- 

 tellum complete in xiii to xxi. Penial setre not ornamented (? ); common setce, 3 and A 

 further apa)t than 1 and 2. Oviducts, two separate pores in front of 1 and 2, on small 

 papilke. Gizzards in viii and ix. Calciferons gland S pairs in xv, xin 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. 



Definition. Length 40 to 00 mm.; number of somites 97. First dorsal pore 

 between v/vi. Clitellum incomplete in all somites, xiii to xx. Penial setm, the largest 

 vnth five to eight notches, the smaller spoonlike and slightly forked; common setm couples 

 equidistant. Oviducts op)ev. in one single pore on a median papilla in xiv. Gizzard two 

 in vii. Calciferous gland three 2>airs in xv, xvi and xvii. Sperm-sacs one jxiir in xi. 

 Nephridia in three rows on either side. Spermatheca, the basal part ivith a single small 

 diverticulum. Saculated intestine begins in xxi. Color dingy fiesh. Habitat, Venezuela 

 [and Hamburg). 



Benhamia palmicola n. subsp. 



Definition. Length 50 to GO mm.; number of somites 90. Skin not pigmented. 

 First dorsal p>ore between ivjv. Clitellum incomplete in all somites. Penial setce, largest 

 with four notches, the smaller one spoonlike and forked; common sette about equal dis- 

 tance betioeen the dorsal and ventral as betiveeji the ventral couples. Oviducts open in one 

 single pore on a median papilla. Gizzards both in viii. Calciferous gland 3 pairs in 



