There were 2 accepted species found [distribution filter:
1 Pelecyphora aselliformis Ehrenb. distributionfilter: global
homotypic synonyms:
Mammillaria aselliformis (Ehrenb.) H.P.Kelsey & Dayton;
links:    
IPNI (International Plant Names Index)   
WFO (World Flora Online)   
Google   
Flickr
2 Pelecyphora strobiliformis Frić & Schelle distributionfilter: global
links:    
WFO (World Flora Online)   
Google   
Flickr